Bump version to v0.4.9 (#11872)

## Summary

This PR makes the `ruff_db` a required crate for `ruff_python_semantic`.

Refer
https://github.com/astral-sh/ruff/actions/runs/9516626143/job/26233307158?pr=11872

## Test Plan

1. `maturin sdist --out dist`
2. `tar -xf dist/ruff-0.4.8.tar.gz --directory=dist/ruff-0.4.8`
3. `pip install dist/ruff-0.4.8.tar.gz` works

.cargo/config.toml

@@ -1,3 +1,10 @@
 [alias]
 dev = "run --package ruff_dev --bin ruff_dev"
 benchmark = "bench -p ruff_benchmark --bench linter --bench formatter --"
+
+# statically link the C runtime so the executable does not depend on
+# that shared/dynamic library.
+#
+# See: https://github.com/astral-sh/ruff/issues/11503
+[target.'cfg(all(target_env="msvc", target_os = "windows"))']
+rustflags = ["-C", "target-feature=+crt-static"]

.github/CODEOWNERS

@@ -15,3 +15,6 @@
 
 # Script for fuzzing the parser
 /scripts/fuzz-parser/ @AlexWaygood
+
+# red-knot
+/crates/red_knot/ @carljm @MichaReiser

.github/renovate.json5

@@ -27,9 +27,27 @@
       // Group upload/download artifact updates, the versions are dependent
       groupName: "Artifact GitHub Actions dependencies",
       matchManagers: ["github-actions"],
+      matchDatasources: ["gitea-tags", "github-tags"],
       matchPackagePatterns: ["actions/.*-artifact"],
       description: "Weekly update of artifact-related GitHub Actions dependencies",
     },
+    {
+      // This package rule disables updates for GitHub runners:
+      // we'd only pin them to a specific version
+      // if there was a deliberate reason to do so
+      groupName: "GitHub runners",
+      matchManagers: ["github-actions"],
+      matchDatasources: ["github-runners"],
+      description: "Disable PRs updating GitHub runners (e.g. 'runs-on: macos-14')",
+      enabled: false,
+    },
+    {
+      // Disable updates of `zip-rs`; intentionally pinned for now due to ownership change
+      // See: https://github.com/astral-sh/uv/issues/3642
+      matchPackagePatterns: ["zip"],
+      matchManagers: ["cargo"],
+      enabled: false,
+    },
     {
       groupName: "pre-commit dependencies",
       matchManagers: ["pre-commit"],

.github/workflows/ci.yaml

@@ -167,6 +167,9 @@ jobs:
       - uses: Swatinem/rust-cache@v2
       - name: "Run tests"
         shell: bash
+        env:
+          # Workaround for <https://github.com/nextest-rs/nextest/issues/1493>.
+          RUSTUP_WINDOWS_PATH_ADD_BIN: 1
         run: |
           cargo nextest run --all-features --profile ci
           cargo test --all-features --doc
@@ -209,6 +212,38 @@ jobs:
       - name: "Build"
         run: cargo build --release --locked
 
+  cargo-build-msrv:
+    name: "cargo build (msrv)"
+    runs-on: ubuntu-latest
+    needs: determine_changes
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
+    timeout-minutes: 20
+    steps:
+      - uses: actions/checkout@v4
+      - uses: SebRollen/toml-action@v1.2.0
+        id: msrv
+        with:
+          file: "Cargo.toml"
+          field: "workspace.package.rust-version"
+      - name: "Install Rust toolchain"
+        run: rustup default ${{ steps.msrv.outputs.value }}
+      - name: "Install mold"
+        uses: rui314/setup-mold@v1
+      - name: "Install cargo nextest"
+        uses: taiki-e/install-action@v2
+        with:
+          tool: cargo-nextest
+      - name: "Install cargo insta"
+        uses: taiki-e/install-action@v2
+        with:
+          tool: cargo-insta
+      - uses: Swatinem/rust-cache@v2
+      - name: "Run tests"
+        shell: bash
+        env:
+          NEXTEST_PROFILE: "ci"
+        run: cargo +${{ steps.msrv.outputs.value }} insta test --all-features --unreferenced reject --test-runner nextest
+
   cargo-fuzz:
     name: "cargo fuzz"
     runs-on: ubuntu-latest
@@ -303,7 +338,7 @@ jobs:
           name: ruff
           path: target/debug
 
-      - uses: dawidd6/action-download-artifact@v3
+      - uses: dawidd6/action-download-artifact@v5
         name: Download baseline Ruff binary
         with:
           name: ruff
@@ -395,22 +430,16 @@ jobs:
           name: ecosystem-result
           path: ecosystem-result
 
-  cargo-udeps:
-    name: "cargo udeps"
+  cargo-shear:
+    name: "cargo shear"
     runs-on: ubuntu-latest
     needs: determine_changes
     if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
-    timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
-      - name: "Install nightly Rust toolchain"
-        # Only pinned to make caching work, update freely
-        run: rustup toolchain install nightly-2023-10-15
-      - uses: Swatinem/rust-cache@v2
-      - name: "Install cargo-udeps"
-        uses: taiki-e/install-action@cargo-udeps
-      - name: "Run cargo-udeps"
-        run: cargo +nightly-2023-10-15 udeps
+      - uses: cargo-bins/cargo-binstall@main
+      - run: cargo binstall --no-confirm cargo-shear
+      - run: cargo shear
 
   python-package:
     name: "python package"

.github/workflows/docs.yaml

@@ -47,7 +47,7 @@ jobs:
         run: mkdocs build --strict -f mkdocs.public.yml
       - name: "Deploy to Cloudflare Pages"
         if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        uses: cloudflare/wrangler-action@v3.4.1
+        uses: cloudflare/wrangler-action@v3.6.1
         with:
           apiToken: ${{ secrets.CF_API_TOKEN }}
           accountId: ${{ secrets.CF_ACCOUNT_ID }}

.github/workflows/playground.yaml

@@ -40,7 +40,7 @@ jobs:
         working-directory: playground
       - name: "Deploy to Cloudflare Pages"
         if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        uses: cloudflare/wrangler-action@v3.4.1
+        uses: cloudflare/wrangler-action@v3.6.1
         with:
           apiToken: ${{ secrets.CF_API_TOKEN }}
           accountId: ${{ secrets.CF_ACCOUNT_ID }}

.github/workflows/pr-comment.yaml

@@ -17,7 +17,7 @@ jobs:
   comment:
     runs-on: ubuntu-latest
     steps:
-      - uses: dawidd6/action-download-artifact@v3
+      - uses: dawidd6/action-download-artifact@v5
         name: Download pull request number
         with:
           name: pr-number
@@ -32,7 +32,7 @@ jobs:
             echo "pr-number=$(<pr-number)" >> $GITHUB_OUTPUT
           fi
 
-      - uses: dawidd6/action-download-artifact@v3
+      - uses: dawidd6/action-download-artifact@v5
         name: "Download ecosystem results"
         id: download-ecosystem-result
         if: steps.pr-number.outputs.pr-number

.github/workflows/release.yaml

@@ -163,6 +163,9 @@ jobs:
         with:
           target: ${{ matrix.platform.target }}
           args: --release --locked --out dist
+        env:
+          # aarch64 build fails, see https://github.com/PyO3/maturin/issues/2110
+          XWIN_VERSION: 16
       - name: "Test wheel"
         if: ${{ !startsWith(matrix.platform.target, 'aarch64') }}
         shell: bash

.github/workflows/sync_typeshed.yaml

@@ -0,0 +1,80 @@
+name: Sync typeshed
+
+on:
+  workflow_dispatch:
+  schedule:
+    # Run on the 1st and the 15th of every month:
+    - cron: "0 0 1,15 * *"
+
+env:
+  FORCE_COLOR: 1
+  GH_TOKEN: ${{ github.token }}
+
+jobs:
+  sync:
+    name: Sync typeshed
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    # Don't run the cron job on forks:
+    if: ${{ github.repository == 'astral-sh/ruff' || github.event_name != 'schedule' }}
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - uses: actions/checkout@v4
+        name: Checkout Ruff
+        with:
+          path: ruff
+      - uses: actions/checkout@v4
+        name: Checkout typeshed
+        with:
+          repository: python/typeshed
+          path: typeshed
+      - name: Setup git
+        run: |
+          git config --global user.name typeshedbot
+          git config --global user.email '<>'
+      - name: Sync typeshed
+        id: sync
+        run: |
+          rm -rf ruff/crates/red_knot/vendor/typeshed
+          mkdir ruff/crates/red_knot/vendor/typeshed
+          cp typeshed/README.md ruff/crates/red_knot/vendor/typeshed
+          cp typeshed/LICENSE ruff/crates/red_knot/vendor/typeshed
+          cp -r typeshed/stdlib ruff/crates/red_knot/vendor/typeshed/stdlib
+          rm -rf ruff/crates/red_knot/vendor/typeshed/stdlib/@tests
+          git -C typeshed rev-parse HEAD > ruff/crates/red_knot/vendor/typeshed/source_commit.txt
+      - name: Commit the changes
+        id: commit
+        if: ${{ steps.sync.outcome == 'success' }}
+        run: |
+          cd ruff
+          git checkout -b typeshedbot/sync-typeshed
+          git add .
+          git diff --staged --quiet || git commit -m "Sync typeshed. Source commit: https://github.com/python/typeshed/commit/$(git -C ../typeshed rev-parse HEAD)"
+      - name: Create a PR
+        if: ${{ steps.sync.outcome == 'success' && steps.commit.outcome == 'success' }}
+        run: |
+          cd ruff
+          git push --force origin typeshedbot/sync-typeshed
+          gh pr list --repo $GITHUB_REPOSITORY --head typeshedbot/sync-typeshed --json id --jq length | grep 1 && exit 0 # exit if there is existing pr
+          gh pr create --title "Sync vendored typeshed stubs" --body "Close and reopen this PR to trigger CI" --label "internal"
+
+  create-issue-on-failure:
+    name: Create an issue if the typeshed sync failed
+    runs-on: ubuntu-latest
+    needs: [sync]
+    if: ${{ github.repository == 'astral-sh/ruff' && always() && github.event_name == 'schedule' && needs.sync.result == 'failure' }}
+    permissions:
+      issues: write
+    steps:
+      - uses: actions/github-script@v7
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            await github.rest.issues.create({
+              owner: "astral-sh",
+              repo: "ruff",
+              title: `Automated typeshed sync failed on ${new Date().toDateString()}`,
+              body: "Runs are listed here: https://github.com/astral-sh/ruff/actions/workflows/sync_typeshed.yaml",
+            })

.pre-commit-config.yaml

@@ -2,6 +2,7 @@ fail_fast: true
 
 exclude: |
   (?x)^(
+    crates/red_knot/vendor/.*|
     crates/ruff_linter/resources/.*|
     crates/ruff_linter/src/rules/.*/snapshots/.*|
     crates/ruff/resources/.*|
@@ -13,7 +14,7 @@ exclude: |
 
 repos:
   - repo: https://github.com/abravalheri/validate-pyproject
-    rev: v0.16
+    rev: v0.18
     hooks:
       - id: validate-pyproject
 
@@ -31,7 +32,7 @@ repos:
           )$
 
   - repo: https://github.com/igorshubovych/markdownlint-cli
-    rev: v0.39.0
+    rev: v0.41.0
     hooks:
       - id: markdownlint-fix
         exclude: |
@@ -41,7 +42,7 @@ repos:
           )$
 
   - repo: https://github.com/crate-ci/typos
-    rev: v1.20.10
+    rev: v1.22.3
     hooks:
       - id: typos
 
@@ -55,7 +56,7 @@ repos:
         pass_filenames: false # This makes it a lot faster
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.4.2
+    rev: v0.4.8
     hooks:
       - id: ruff-format
       - id: ruff

.vscode/extensions.json

@@ -0,0 +1,5 @@
+{
+    "recommendations": [
+        "rust-lang.rust-analyzer"
+    ]
+}

.vscode/settings.json

@@ -0,0 +1,6 @@
+{
+    "rust-analyzer.check.extraArgs": [
+        "--all-features"
+    ],
+    "rust-analyzer.check.command": "clippy",
+}

CHANGELOG.md

@@ -1,5 +1,222 @@
 # Changelog
 
+## 0.4.9
+
+### Preview features
+
+- \[`pylint`\] Implement `consider-dict-items` (`C0206`) ([#11688](https://github.com/astral-sh/ruff/pull/11688))
+- \[`refurb`\] Implement `repeated-global` (`FURB154`) ([#11187](https://github.com/astral-sh/ruff/pull/11187))
+
+### Rule changes
+
+- \[`pycodestyle`\] Adapt fix for `E203` to work identical to `ruff format` ([#10999](https://github.com/astral-sh/ruff/pull/10999))
+
+### Formatter
+
+- Fix formatter instability for lines only consisting of zero-width characters ([#11748](https://github.com/astral-sh/ruff/pull/11748))
+
+### Server
+
+- Add supported commands in server capabilities ([#11850](https://github.com/astral-sh/ruff/pull/11850))
+- Use real file path when available in `ruff server` ([#11800](https://github.com/astral-sh/ruff/pull/11800))
+- Improve error message when a command is run on an unavailable document ([#11823](https://github.com/astral-sh/ruff/pull/11823))
+- Introduce the `ruff.printDebugInformation` command ([#11831](https://github.com/astral-sh/ruff/pull/11831))
+- Tracing system now respects log level and trace level, with options to log to a file ([#11747](https://github.com/astral-sh/ruff/pull/11747))
+
+### CLI
+
+- Handle non-printable characters in diff view ([#11687](https://github.com/astral-sh/ruff/pull/11687))
+
+### Bug fixes
+
+- \[`refurb`\] Avoid suggesting starmap when arguments are used outside call (`FURB140`) ([#11830](https://github.com/astral-sh/ruff/pull/11830))
+- \[`flake8-bugbear`\] Avoid panic in `B909` when checking large loop blocks ([#11772](https://github.com/astral-sh/ruff/pull/11772))
+- \[`refurb`\] Fix misbehavior of `operator.itemgetter` when getter param is a tuple (`FURB118`) ([#11774](https://github.com/astral-sh/ruff/pull/11774))
+
+## 0.4.8
+
+### Performance
+
+- Linter performance has been improved by around 10% on some microbenchmarks by refactoring the lexer and parser to maintain synchronicity between them ([#11457](https://github.com/astral-sh/ruff/pull/11457))
+
+### Preview features
+
+- \[`flake8-bugbear`\] Implement `return-in-generator` (`B901`) ([#11644](https://github.com/astral-sh/ruff/pull/11644))
+- \[`flake8-pyi`\] Implement `PYI063` ([#11699](https://github.com/astral-sh/ruff/pull/11699))
+- \[`pygrep_hooks`\] Check blanket ignores via file-level pragmas (`PGH004`) ([#11540](https://github.com/astral-sh/ruff/pull/11540))
+
+### Rule changes
+
+- \[`pyupgrade`\] Update `UP035` for Python 3.13 and the latest version of `typing_extensions` ([#11693](https://github.com/astral-sh/ruff/pull/11693))
+- \[`numpy`\] Update `NPY001` rule for NumPy 2.0 ([#11735](https://github.com/astral-sh/ruff/pull/11735))
+
+### Server
+
+- Formatting a document with syntax problems no longer spams a visible error popup ([#11745](https://github.com/astral-sh/ruff/pull/11745))
+
+### CLI
+
+- Add RDJson support for `--output-format` flag ([#11682](https://github.com/astral-sh/ruff/pull/11682))
+
+### Bug fixes
+
+- \[`pyupgrade`\] Write empty string in lieu of panic when fixing `UP032` ([#11696](https://github.com/astral-sh/ruff/pull/11696))
+- \[`flake8-simplify`\] Simplify double negatives in `SIM103` ([#11684](https://github.com/astral-sh/ruff/pull/11684))
+- Ensure the expression generator adds a newline before `type` statements ([#11720](https://github.com/astral-sh/ruff/pull/11720))
+- Respect per-file ignores for blanket and redirected noqa rules ([#11728](https://github.com/astral-sh/ruff/pull/11728))
+
+## 0.4.7
+
+### Preview features
+
+- \[`flake8-pyi`\] Implement `PYI064` ([#11325](https://github.com/astral-sh/ruff/pull/11325))
+- \[`flake8-pyi`\] Implement `PYI066` ([#11541](https://github.com/astral-sh/ruff/pull/11541))
+- \[`flake8-pyi`\] Implement `PYI057` ([#11486](https://github.com/astral-sh/ruff/pull/11486))
+- \[`pyflakes`\] Enable `F822` in `__init__.py` files by default ([#11370](https://github.com/astral-sh/ruff/pull/11370))
+
+### Formatter
+
+- Fix incorrect placement of trailing stub function comments ([#11632](https://github.com/astral-sh/ruff/pull/11632))
+
+### Server
+
+- Respect file exclusions in `ruff server` ([#11590](https://github.com/astral-sh/ruff/pull/11590))
+- Add support for documents not exist on disk ([#11588](https://github.com/astral-sh/ruff/pull/11588))
+- Add Vim and Kate setup guide for `ruff server` ([#11615](https://github.com/astral-sh/ruff/pull/11615))
+
+### Bug fixes
+
+- Avoid removing newlines between docstring headers and rST blocks ([#11609](https://github.com/astral-sh/ruff/pull/11609))
+- Infer indentation with imports when logical indent is absent ([#11608](https://github.com/astral-sh/ruff/pull/11608))
+- Use char index rather than position for indent slice ([#11645](https://github.com/astral-sh/ruff/pull/11645))
+- \[`flake8-comprehension`\] Strip parentheses around generators in `C400` ([#11607](https://github.com/astral-sh/ruff/pull/11607))
+- Mark `repeated-isinstance-calls` as unsafe on Python 3.10 and later ([#11622](https://github.com/astral-sh/ruff/pull/11622))
+
+## 0.4.6
+
+### Breaking changes
+
+- Use project-relative paths when calculating GitLab fingerprints ([#11532](https://github.com/astral-sh/ruff/pull/11532))
+- Bump minimum supported Windows version to Windows 10 ([#11613](https://github.com/astral-sh/ruff/pull/11613))
+
+### Preview features
+
+- \[`flake8-async`\] Sleep with >24 hour interval should usually sleep forever (`ASYNC116`) ([#11498](https://github.com/astral-sh/ruff/pull/11498))
+
+### Rule changes
+
+- \[`numpy`\] Add missing functions to NumPy 2.0 migration rule ([#11528](https://github.com/astral-sh/ruff/pull/11528))
+- \[`mccabe`\] Consider irrefutable pattern similar to `if .. else` for `C901` ([#11565](https://github.com/astral-sh/ruff/pull/11565))
+- Consider `match`-`case` statements for `C901`, `PLR0912`, and `PLR0915` ([#11521](https://github.com/astral-sh/ruff/pull/11521))
+- Remove empty strings when converting to f-string (`UP032`) ([#11524](https://github.com/astral-sh/ruff/pull/11524))
+- \[`flake8-bandit`\] `request-without-timeout` should warn for `requests.request` ([#11548](https://github.com/astral-sh/ruff/pull/11548))
+- \[`flake8-self`\] Ignore sunder accesses in `flake8-self` rules ([#11546](https://github.com/astral-sh/ruff/pull/11546))
+- \[`pyupgrade`\] Lint for `TypeAliasType` usages (`UP040`) ([#11530](https://github.com/astral-sh/ruff/pull/11530))
+
+### Server
+
+- Respect excludes in `ruff server` configuration discovery ([#11551](https://github.com/astral-sh/ruff/pull/11551))
+- Use default settings if initialization options is empty or not provided ([#11566](https://github.com/astral-sh/ruff/pull/11566))
+- `ruff server` correctly treats `.pyi` files as stub files ([#11535](https://github.com/astral-sh/ruff/pull/11535))
+- `ruff server` searches for configuration in parent directories ([#11537](https://github.com/astral-sh/ruff/pull/11537))
+- `ruff server`: An empty code action filter no longer returns notebook source actions ([#11526](https://github.com/astral-sh/ruff/pull/11526))
+
+### Bug fixes
+
+- \[`flake8-logging-format`\] Fix autofix title in `logging-warn` (`G010`) ([#11514](https://github.com/astral-sh/ruff/pull/11514))
+- \[`refurb`\] Avoid recommending `operator.itemgetter` with dependence on lambda arguments ([#11574](https://github.com/astral-sh/ruff/pull/11574))
+- \[`flake8-simplify`\] Avoid recommending context manager in `__enter__` implementations ([#11575](https://github.com/astral-sh/ruff/pull/11575))
+- Create intermediary directories for `--output-file` ([#11550](https://github.com/astral-sh/ruff/pull/11550))
+- Propagate reads on global variables ([#11584](https://github.com/astral-sh/ruff/pull/11584))
+- Treat all `singledispatch` arguments as runtime-required ([#11523](https://github.com/astral-sh/ruff/pull/11523))
+
+## 0.4.5
+
+### Ruff's language server is now in Beta
+
+`v0.4.5` marks the official Beta release of `ruff server`, an integrated language server built into Ruff.
+`ruff server` supports the same feature set as `ruff-lsp`, powering linting, formatting, and
+code fixes in Ruff's editor integrations -- but with superior performance and
+no installation required. We'd love your feedback!
+
+You can enable `ruff server` in the [VS Code extension](https://github.com/astral-sh/ruff-vscode?tab=readme-ov-file#enabling-the-rust-based-language-server) today.
+
+To read more about this exciting milestone, check out our [blog post](https://astral.sh/blog/ruff-v0.4.5)!
+
+### Rule changes
+
+- \[`flake8-future-annotations`\] Reword `future-rewritable-type-annotation` (`FA100`) message ([#11381](https://github.com/astral-sh/ruff/pull/11381))
+- \[`isort`\] Expanded the set of standard-library modules to include `_string`, etc. ([#11374](https://github.com/astral-sh/ruff/pull/11374))
+- \[`pycodestyle`\] Consider soft keywords for `E27` rules ([#11446](https://github.com/astral-sh/ruff/pull/11446))
+- \[`pyflakes`\] Recommend adding unused import bindings to `__all__` ([#11314](https://github.com/astral-sh/ruff/pull/11314))
+- \[`pyflakes`\] Update documentation and deprecate `ignore_init_module_imports` ([#11436](https://github.com/astral-sh/ruff/pull/11436))
+- \[`pyupgrade`\] Mark quotes as unnecessary for non-evaluated annotations ([#11485](https://github.com/astral-sh/ruff/pull/11485))
+
+### Formatter
+
+- Avoid multiline quotes warning with `quote-style = preserve` ([#11490](https://github.com/astral-sh/ruff/pull/11490))
+
+### Server
+
+- Support Jupyter Notebook files ([#11206](https://github.com/astral-sh/ruff/pull/11206))
+- Support `noqa` comment code actions ([#11276](https://github.com/astral-sh/ruff/pull/11276))
+- Fix automatic configuration reloading ([#11492](https://github.com/astral-sh/ruff/pull/11492))
+- Fix several issues with configuration in Neovim and Helix ([#11497](https://github.com/astral-sh/ruff/pull/11497))
+
+### CLI
+
+- Add `--output-format` as a CLI option for `ruff config` ([#11438](https://github.com/astral-sh/ruff/pull/11438))
+
+### Bug fixes
+
+- Avoid `PLE0237` for property with setter ([#11377](https://github.com/astral-sh/ruff/pull/11377))
+- Avoid `TCH005` for `if` stmt with `elif`/`else` block ([#11376](https://github.com/astral-sh/ruff/pull/11376))
+- Avoid flagging `__future__` annotations as required for non-evaluated type annotations ([#11414](https://github.com/astral-sh/ruff/pull/11414))
+- Check for ruff executable in 'bin' directory as installed by 'pip install --target'. ([#11450](https://github.com/astral-sh/ruff/pull/11450))
+- Sort edits prior to deduplicating in quotation fix ([#11452](https://github.com/astral-sh/ruff/pull/11452))
+- Treat escaped newline as valid sequence ([#11465](https://github.com/astral-sh/ruff/pull/11465))
+- \[`flake8-pie`\] Preserve parentheses in `unnecessary-dict-kwargs` ([#11372](https://github.com/astral-sh/ruff/pull/11372))
+- \[`pylint`\] Ignore `__slots__` with dynamic values ([#11488](https://github.com/astral-sh/ruff/pull/11488))
+- \[`pylint`\] Remove `try` body from branch counting ([#11487](https://github.com/astral-sh/ruff/pull/11487))
+- \[`refurb`\] Respect operator precedence in `FURB110` ([#11464](https://github.com/astral-sh/ruff/pull/11464))
+
+### Documentation
+
+- Add `--preview` to the README ([#11395](https://github.com/astral-sh/ruff/pull/11395))
+- Add Python 3.13 to list of allowed Python versions ([#11411](https://github.com/astral-sh/ruff/pull/11411))
+- Simplify Neovim setup documentation ([#11489](https://github.com/astral-sh/ruff/pull/11489))
+- Update CONTRIBUTING.md to reflect the new parser ([#11434](https://github.com/astral-sh/ruff/pull/11434))
+- Update server documentation with new migration guide ([#11499](https://github.com/astral-sh/ruff/pull/11499))
+- \[`pycodestyle`\] Clarify motivation for `E713` and `E714` ([#11483](https://github.com/astral-sh/ruff/pull/11483))
+- \[`pyflakes`\] Update docs to describe WAI behavior (F541) ([#11362](https://github.com/astral-sh/ruff/pull/11362))
+- \[`pylint`\] Clearly indicate what is counted as a branch ([#11423](https://github.com/astral-sh/ruff/pull/11423))
+
+## 0.4.4
+
+### Preview features
+
+- \[`pycodestyle`\] Ignore end-of-line comments when determining blank line rules ([#11342](https://github.com/astral-sh/ruff/pull/11342))
+- \[`pylint`\] Detect `pathlib.Path.open` calls in `unspecified-encoding` (`PLW1514`)  ([#11288](https://github.com/astral-sh/ruff/pull/11288))
+- \[`flake8-pyi`\] Implement `PYI059` (`generic-not-last-base-class`) ([#11233](https://github.com/astral-sh/ruff/pull/11233))
+- \[`flake8-pyi`\] Implement `PYI062` (`duplicate-literal-member`) ([#11269](https://github.com/astral-sh/ruff/pull/11269))
+
+### Rule changes
+
+- \[`flake8-boolean-trap`\] Allow passing booleans as positional-only arguments in code such as `set(True)` ([#11287](https://github.com/astral-sh/ruff/pull/11287))
+- \[`flake8-bugbear`\] Ignore enum classes in `cached-instance-method` (`B019`) ([#11312](https://github.com/astral-sh/ruff/pull/11312))
+
+### Server
+
+- Expand tildes when resolving Ruff server configuration file ([#11283](https://github.com/astral-sh/ruff/pull/11283))
+- Fix `ruff server` hanging after Neovim closes ([#11291](https://github.com/astral-sh/ruff/pull/11291))
+- Editor settings are used by default if no file-based configuration exists ([#11266](https://github.com/astral-sh/ruff/pull/11266))
+
+### Bug fixes
+
+- \[`pylint`\] Consider `with` statements for `too-many-branches` (`PLR0912`) ([#11321](https://github.com/astral-sh/ruff/pull/11321))
+- \[`flake8-blind-except`, `tryceratops`\] Respect logged and re-raised expressions in nested statements (`BLE001`, `TRY201`) ([#11301](https://github.com/astral-sh/ruff/pull/11301))
+- Recognise assignments such as `__all__ = builtins.list(["foo", "bar"])` as valid `__all__` definitions ([#11335](https://github.com/astral-sh/ruff/pull/11335))
+
 ## 0.4.3
 
 ### Enhancements
@@ -48,6 +265,10 @@
 - Avoid allocations for isort module names ([#11251](https://github.com/astral-sh/ruff/pull/11251))
 - Build a separate ARM wheel for macOS ([#11149](https://github.com/astral-sh/ruff/pull/11149))
 
+### Windows
+
+- Increase the minimum requirement to Windows 10.
+
 ## 0.4.2
 
 ### Rule changes

CONTRIBUTING.md

@@ -101,6 +101,8 @@ pre-commit run --all-files --show-diff-on-failure  # Rust and Python formatting,
 These checks will run on GitHub Actions when you open your pull request, but running them locally
 will save you time and expedite the merge process.
 
+If you're using VS Code, you can also install the recommended [rust-analyzer](https://marketplace.visualstudio.com/items?itemName=rust-lang.rust-analyzer) extension to get these checks while editing.
+
 Note that many code changes also require updating the snapshot tests, which is done interactively
 after running `cargo test` like so:
 
@@ -637,11 +639,11 @@ Otherwise, follow the instructions from the linux section.
 `cargo dev` is a shortcut for `cargo run --package ruff_dev --bin ruff_dev`. You can run some useful
 utils with it:
 
-- `cargo dev print-ast <file>`: Print the AST of a python file using the
-    [RustPython parser](https://github.com/astral-sh/ruff/tree/main/crates/ruff_python_parser) that is
-    mainly used in Ruff. For `if True: pass # comment`, you can see the syntax tree, the byte offsets
-    for start and stop of each node and also how the `:` token, the comment and whitespace are not
-    represented anymore:
+- `cargo dev print-ast <file>`: Print the AST of a python file using Ruff's
+    [Python parser](https://github.com/astral-sh/ruff/tree/main/crates/ruff_python_parser).
+    For `if True: pass # comment`, you can see the syntax tree, the byte offsets for start and
+    stop of each node and also how the `:` token, the comment and whitespace are not represented
+    anymore:
 
 ```text
 [

Cargo.toml

@@ -4,7 +4,7 @@ resolver = "2"
 
 [workspace.package]
 edition = "2021"
-rust-version = "1.71"
+rust-version = "1.75"
 homepage = "https://docs.astral.sh/ruff"
 documentation = "https://docs.astral.sh/ruff"
 repository = "https://github.com/astral-sh/ruff"
@@ -12,6 +12,29 @@ authors = ["Charlie Marsh <charlie.r.marsh@gmail.com>"]
 license = "MIT"
 
 [workspace.dependencies]
+ruff = { path = "crates/ruff" }
+ruff_cache = { path = "crates/ruff_cache" }
+ruff_db = { path = "crates/ruff_db" }
+ruff_diagnostics = { path = "crates/ruff_diagnostics" }
+ruff_formatter = { path = "crates/ruff_formatter" }
+ruff_index = { path = "crates/ruff_index" }
+ruff_linter = { path = "crates/ruff_linter" }
+ruff_macros = { path = "crates/ruff_macros" }
+ruff_notebook = { path = "crates/ruff_notebook" }
+ruff_python_ast = { path = "crates/ruff_python_ast" }
+ruff_python_codegen = { path = "crates/ruff_python_codegen" }
+ruff_python_formatter = { path = "crates/ruff_python_formatter" }
+ruff_python_index = { path = "crates/ruff_python_index" }
+ruff_python_literal = { path = "crates/ruff_python_literal" }
+ruff_python_parser = { path = "crates/ruff_python_parser" }
+ruff_python_semantic = { path = "crates/ruff_python_semantic" }
+ruff_python_stdlib = { path = "crates/ruff_python_stdlib" }
+ruff_python_trivia = { path = "crates/ruff_python_trivia" }
+ruff_server = { path = "crates/ruff_server" }
+ruff_source_file = { path = "crates/ruff_source_file" }
+ruff_text_size = { path = "crates/ruff_text_size" }
+ruff_workspace = { path = "crates/ruff_workspace" }
+
 aho-corasick = { version = "1.1.3" }
 annotate-snippets = { version = "0.9.2", features = ["color"] }
 anyhow = { version = "1.0.80" }
@@ -20,6 +43,7 @@ bincode = { version = "1.3.3" }
 bitflags = { version = "2.5.0" }
 bstr = { version = "1.9.1" }
 cachedir = { version = "0.3.1" }
+camino = { version = "1.1.7" }
 chrono = { version = "0.4.35", default-features = false, features = ["clock"] }
 clap = { version = "4.5.3", features = ["derive"] }
 clap_complete_command = { version = "0.5.1" }
@@ -37,11 +61,9 @@ drop_bomb = { version = "0.1.5" }
 env_logger = { version = "0.11.0" }
 fern = { version = "0.6.1" }
 filetime = { version = "0.2.23" }
-fs-err = { version = "2.11.0" }
 glob = { version = "0.3.1" }
 globset = { version = "0.4.14" }
 hashbrown = "0.14.3"
-hexf-parse = { version = "0.2.1" }
 ignore = { version = "0.4.22" }
 imara-diff = { version = "0.1.5" }
 imperative = { version = "1.0.4" }
@@ -52,15 +74,16 @@ insta = { version = "1.35.1", feature = ["filters", "glob"] }
 insta-cmd = { version = "0.6.0" }
 is-macro = { version = "0.3.5" }
 is-wsl = { version = "0.4.0" }
-itertools = { version = "0.12.1" }
+itertools = { version = "0.13.0" }
 js-sys = { version = "0.3.69" }
 jod-thread = { version = "0.1.2" }
-lexical-parse-float = { version = "0.8.0", features = ["format"] }
 libc = { version = "0.2.153" }
 libcst = { version = "1.1.0", default-features = false }
 log = { version = "0.4.17" }
 lsp-server = { version = "0.7.6" }
-lsp-types = { version = "0.95.0", features = ["proposed"] }
+lsp-types = { git = "https://github.com/astral-sh/lsp-types.git", rev = "3512a9f", features = [
+  "proposed",
+] }
 matchit = { version = "0.8.1" }
 memchr = { version = "2.7.1" }
 mimalloc = { version = "0.1.39" }
@@ -80,15 +103,17 @@ quote = { version = "1.0.23" }
 rand = { version = "0.8.5" }
 rayon = { version = "1.10.0" }
 regex = { version = "1.10.2" }
-result-like = { version = "0.5.0" }
 rustc-hash = { version = "1.1.0" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", package = "salsa-2022", rev = "05b4e3ebdcdc47730cdd359e7e97fb2470527279" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
 serde-wasm-bindgen = { version = "0.6.4" }
 serde_json = { version = "1.0.113" }
 serde_test = { version = "1.0.152" }
-serde_with = { version = "3.6.0", default-features = false, features = ["macros"] }
+serde_with = { version = "3.6.0", default-features = false, features = [
+  "macros",
+] }
 shellexpand = { version = "3.0.0" }
 similar = { version = "2.4.0", features = ["inline"] }
 smallvec = { version = "1.13.2" }
@@ -113,11 +138,17 @@ unicode_names2 = { version = "1.2.2" }
 unicode-normalization = { version = "0.1.23" }
 ureq = { version = "2.9.6" }
 url = { version = "2.5.0" }
-uuid = { version = "1.6.1", features = ["v4", "fast-rng", "macro-diagnostics", "js"] }
+uuid = { version = "1.6.1", features = [
+  "v4",
+  "fast-rng",
+  "macro-diagnostics",
+  "js",
+] }
 walkdir = { version = "2.3.2" }
 wasm-bindgen = { version = "0.2.92" }
 wasm-bindgen-test = { version = "0.3.42" }
 wild = { version = "2" }
+zip = { version = "0.6.6", default-features = false, features = ["zstd"] }
 
 [workspace.lints.rust]
 unsafe_code = "warn"
@@ -130,6 +161,7 @@ char_lit_as_u8 = "allow"
 collapsible_else_if = "allow"
 collapsible_if = "allow"
 implicit_hasher = "allow"
+map_unwrap_or = "allow"
 match_same_arms = "allow"
 missing_errors_doc = "allow"
 missing_panics_doc = "allow"

README.md

@@ -28,7 +28,7 @@ An extremely fast Python linter and code formatter, written in Rust.
 - ⚡️ 10-100x faster than existing linters (like Flake8) and formatters (like Black)
 - 🐍 Installable via `pip`
 - 🛠️ `pyproject.toml` support
-- 🤝 Python 3.12 compatibility
+- 🤝 Python 3.13 compatibility
 - ⚖️ Drop-in parity with [Flake8](https://docs.astral.sh/ruff/faq/#how-does-ruff-compare-to-flake8), isort, and Black
 - 📦 Built-in caching, to avoid re-analyzing unchanged files
 - 🔧 Fix support, for automatic error correction (e.g., automatically remove unused imports)
@@ -152,7 +152,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.4.3
+  rev: v0.4.9
   hooks:
     # Run the linter.
     - id: ruff
@@ -266,6 +266,11 @@ The remaining configuration options can be provided through a catch-all `--confi
 ruff check --config "lint.per-file-ignores = {'some_file.py' = ['F841']}"
 ```
 
+To opt in to the latest lint rules, formatter style changes, interface updates, and more, enable
+[preview mode](https://docs.astral.sh/ruff/rules/) by setting `preview = true` in your configuration
+file or passing `--preview` on the command line. Preview mode enables a collection of unstable
+features that may change prior to stabilization.
+
 See `ruff help` for more on Ruff's top-level commands, or `ruff help check` and `ruff help format`
 for more on the linting and formatting commands, respectively.
 
@@ -403,6 +408,7 @@ Ruff is used by a number of major open-source projects and companies, including:
 - [Dagster](https://github.com/dagster-io/dagster)
 - Databricks ([MLflow](https://github.com/mlflow/mlflow))
 - [FastAPI](https://github.com/tiangolo/fastapi)
+- [Godot](https://github.com/godotengine/godot)
 - [Gradio](https://github.com/gradio-app/gradio)
 - [Great Expectations](https://github.com/great-expectations/great_expectations)
 - [HTTPX](https://github.com/encode/httpx)
@@ -425,9 +431,10 @@ Ruff is used by a number of major open-source projects and companies, including:
 - Microsoft ([Semantic Kernel](https://github.com/microsoft/semantic-kernel),
     [ONNX Runtime](https://github.com/microsoft/onnxruntime),
     [LightGBM](https://github.com/microsoft/LightGBM))
-- Modern Treasury ([Python SDK](https://github.com/Modern-Treasury/modern-treasury-python-sdk))
+- Modern Treasury ([Python SDK](https://github.com/Modern-Treasury/modern-treasury-python))
 - Mozilla ([Firefox](https://github.com/mozilla/gecko-dev))
 - [Mypy](https://github.com/python/mypy)
+- [Nautobot](https://github.com/nautobot/nautobot)
 - Netflix ([Dispatch](https://github.com/Netflix/dispatch))
 - [Neon](https://github.com/neondatabase/neon)
 - [Nokia](https://nokia.com/)
@@ -462,6 +469,7 @@ Ruff is used by a number of major open-source projects and companies, including:
 - [Sphinx](https://github.com/sphinx-doc/sphinx)
 - [Stable Baselines3](https://github.com/DLR-RM/stable-baselines3)
 - [Starlette](https://github.com/encode/starlette)
+- [Streamlit](https://github.com/streamlit/streamlit)
 - [The Algorithms](https://github.com/TheAlgorithms/Python)
 - [Vega-Altair](https://github.com/altair-viz/altair)
 - WordPress ([Openverse](https://github.com/WordPress/openverse))

_typos.toml

@@ -1,6 +1,6 @@
 [files]
 # https://github.com/crate-ci/typos/issues/868
-extend-exclude = ["**/resources/**/*", "**/snapshots/**/*"]
+extend-exclude = ["crates/red_knot/vendor/**/*", "**/resources/**/*", "**/snapshots/**/*"]
 
 [default.extend-words]
 "arange" = "arange"  # e.g. `numpy.arange`
@@ -11,6 +11,7 @@ ned = "ned"
 pn = "pn"  # `import panel as pd` is a thing
 poit = "poit"
 BA = "BA" # acronym for "Bad Allowed", used in testing.
+jod = "jod" # e.g., `jod-thread`
 
 [default]
 extend-ignore-re = [

clippy.toml

@@ -1,12 +1,13 @@
 doc-valid-idents = [
-  "StackOverflow",
+  "..",
   "CodeQL",
+  "FastAPI",
   "IPython",
-  "NumPy",
+  "LangChain",
   "LibCST",
+  "McCabe",
+  "NumPy",
   "SCREAMING_SNAKE_CASE",
   "SQLAlchemy",
-  "McCabe",
-  "FastAPI",
-  "..",
+  "StackOverflow",
 ]

crates/red_knot/Cargo.toml

@@ -12,33 +12,37 @@ license.workspace = true
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-ruff_python_parser = { path = "../ruff_python_parser" }
-ruff_python_ast = { path = "../ruff_python_ast" }
-ruff_python_trivia = { path = "../ruff_python_trivia" }
-ruff_text_size = { path = "../ruff_text_size" }
-ruff_index = { path = "../ruff_index" }
-ruff_notebook = { path = "../ruff_notebook" }
+ruff_python_parser = { workspace = true }
+ruff_python_ast = { workspace = true }
+ruff_python_stdlib = { workspace = true }
+ruff_text_size = { workspace = true }
+ruff_index = { workspace = true }
+ruff_notebook = { workspace = true }
 
 anyhow = { workspace = true }
 bitflags = { workspace = true }
-ctrlc = "3.4.4"
 crossbeam = { workspace = true }
+ctrlc = { version = "3.4.4" }
 dashmap = { workspace = true }
 hashbrown = { workspace = true }
 indexmap = { workspace = true }
-log = { workspace = true }
+is-macro = { workspace = true }
 notify = { workspace = true }
 parking_lot = { workspace = true }
 rayon = { workspace = true }
 rustc-hash = { workspace = true }
-smallvec = { workspace = true }
-smol_str = "0.2.1"
+smol_str = { version = "0.2.1" }
 tracing = { workspace = true }
 tracing-subscriber = { workspace = true }
 tracing-tree = { workspace = true }
+zip = { workspace = true }
+
+[build-dependencies]
+zip = { workspace = true }
+walkdir = { workspace = true }
 
 [dev-dependencies]
-textwrap = "0.16.1"
+insta = { workspace = true }
 tempfile = { workspace = true }
 
 [lints]

crates/red_knot/README.md

@@ -0,0 +1,9 @@
+# Red Knot
+
+The Red Knot crate contains code working towards multifile analysis, type inference and, ultimately, type-checking. It's very much a work in progress for now.
+
+## Vendored types for the stdlib
+
+Red Knot vendors [typeshed](https://github.com/python/typeshed)'s stubs for the standard library. The vendored stubs can be found in `crates/red_knot/vendor/typeshed`. The file `crates/red_knot/vendor/typeshed/source_commit.txt` tells you the typeshed commit that our vendored stdlib stubs currently correspond to.
+
+The typeshed stubs are updated every two weeks via an automated PR using the `sync_typeshed.yaml` workflow in the `.github/workflows` directory. This workflow can also be triggered at any time via [workflow dispatch](https://docs.github.com/en/actions/using-workflows/manually-running-a-workflow#running-a-workflow).

crates/red_knot/build.rs

@@ -0,0 +1,73 @@
+//! Build script to package our vendored typeshed files
+//! into a zip archive that can be included in the Ruff binary.
+//!
+//! This script should be automatically run at build time
+//! whenever the script itself changes, or whenever any files
+//! in `crates/red_knot/vendor/typeshed` change.
+
+use std::fs::File;
+use std::path::Path;
+
+use zip::result::ZipResult;
+use zip::write::{FileOptions, ZipWriter};
+use zip::CompressionMethod;
+
+const TYPESHED_SOURCE_DIR: &str = "vendor/typeshed";
+const TYPESHED_ZIP_LOCATION: &str = "/zipped_typeshed.zip";
+
+/// Recursively zip the contents of an entire directory.
+///
+/// This routine is adapted from a recipe at
+/// <https://github.com/zip-rs/zip-old/blob/5d0f198124946b7be4e5969719a7f29f363118cd/examples/write_dir.rs>
+fn zip_dir(directory_path: &str, writer: File) -> ZipResult<File> {
+    let mut zip = ZipWriter::new(writer);
+
+    let options = FileOptions::default()
+        .compression_method(CompressionMethod::Zstd)
+        .unix_permissions(0o644);
+
+    for entry in walkdir::WalkDir::new(directory_path) {
+        let dir_entry = entry.unwrap();
+        let relative_path = dir_entry.path();
+        let name = relative_path
+            .strip_prefix(Path::new(directory_path))
+            .unwrap()
+            .to_str()
+            .expect("Unexpected non-utf8 typeshed path!");
+
+        // Write file or directory explicitly
+        // Some unzip tools unzip files with directory paths correctly, some do not!
+        if relative_path.is_file() {
+            println!("adding file {relative_path:?} as {name:?} ...");
+            zip.start_file(name, options)?;
+            let mut f = File::open(relative_path)?;
+            std::io::copy(&mut f, &mut zip).unwrap();
+        } else if !name.is_empty() {
+            // Only if not root! Avoids path spec / warning
+            // and mapname conversion failed error on unzip
+            println!("adding dir {relative_path:?} as {name:?} ...");
+            zip.add_directory(name, options)?;
+        }
+    }
+    zip.finish()
+}
+
+fn main() {
+    println!("cargo:rerun-if-changed={TYPESHED_SOURCE_DIR}");
+    assert!(
+        Path::new(TYPESHED_SOURCE_DIR).is_dir(),
+        "Where is typeshed?"
+    );
+    let out_dir = std::env::var("OUT_DIR").unwrap();
+
+    // N.B. Deliberately using `format!()` instead of `Path::join()` here,
+    // so that we use `/` as a path separator on all platforms.
+    // That enables us to load the typeshed zip at compile time in `module.rs`
+    // (otherwise we'd have to dynamically determine the exact path to the typeshed zip
+    // based on the default path separator for the specific platform we're on,
+    // which can't be done at compile time.)
+    let zipped_typeshed_location = format!("{out_dir}{TYPESHED_ZIP_LOCATION}");
+
+    let zipped_typeshed = File::create(zipped_typeshed_location).unwrap();
+    zip_dir(TYPESHED_SOURCE_DIR, zipped_typeshed).unwrap();
+}

crates/red_knot/src/ast_ids.rs

@@ -6,8 +6,8 @@ use std::marker::PhantomData;
 use rustc_hash::FxHashMap;
 
 use ruff_index::{Idx, IndexVec};
-use ruff_python_ast::visitor::preorder;
-use ruff_python_ast::visitor::preorder::{PreorderVisitor, TraversalSignal};
+use ruff_python_ast::visitor::source_order;
+use ruff_python_ast::visitor::source_order::{SourceOrderVisitor, TraversalSignal};
 use ruff_python_ast::{
     AnyNodeRef, AstNode, ExceptHandler, ExceptHandlerExceptHandler, Expr, MatchCase, ModModule,
     NodeKind, Parameter, Stmt, StmtAnnAssign, StmtAssign, StmtAugAssign, StmtClassDef,
@@ -91,9 +91,9 @@ impl AstIds {
         while let Some(deferred) = visitor.deferred.pop() {
             match deferred {
                 DeferredNode::FunctionDefinition(def) => {
-                    def.visit_preorder(&mut visitor);
+                    def.visit_source_order(&mut visitor);
                 }
-                DeferredNode::ClassDefinition(def) => def.visit_preorder(&mut visitor),
+                DeferredNode::ClassDefinition(def) => def.visit_source_order(&mut visitor),
             }
         }
 
@@ -182,7 +182,7 @@ impl<'a> AstIdsVisitor<'a> {
     }
 }
 
-impl<'a> PreorderVisitor<'a> for AstIdsVisitor<'a> {
+impl<'a> SourceOrderVisitor<'a> for AstIdsVisitor<'a> {
     fn visit_stmt(&mut self, stmt: &'a Stmt) {
         match stmt {
             Stmt::FunctionDef(def) => {
@@ -226,14 +226,14 @@ impl<'a> PreorderVisitor<'a> for AstIdsVisitor<'a> {
             Stmt::IpyEscapeCommand(_) => {}
         }
 
-        preorder::walk_stmt(self, stmt);
+        source_order::walk_stmt(self, stmt);
     }
 
     fn visit_expr(&mut self, _expr: &'a Expr) {}
 
     fn visit_parameter(&mut self, parameter: &'a Parameter) {
         self.create_id(parameter);
-        preorder::walk_parameter(self, parameter);
+        source_order::walk_parameter(self, parameter);
     }
 
     fn visit_except_handler(&mut self, except_handler: &'a ExceptHandler) {
@@ -243,17 +243,17 @@ impl<'a> PreorderVisitor<'a> for AstIdsVisitor<'a> {
             }
         }
 
-        preorder::walk_except_handler(self, except_handler);
+        source_order::walk_except_handler(self, except_handler);
     }
 
     fn visit_with_item(&mut self, with_item: &'a WithItem) {
         self.create_id(with_item);
-        preorder::walk_with_item(self, with_item);
+        source_order::walk_with_item(self, with_item);
     }
 
     fn visit_match_case(&mut self, match_case: &'a MatchCase) {
         self.create_id(match_case);
-        preorder::walk_match_case(self, match_case);
+        source_order::walk_match_case(self, match_case);
     }
 
     fn visit_type_param(&mut self, type_param: &'a TypeParam) {
@@ -275,10 +275,7 @@ pub struct TypedNodeKey<N: AstNode> {
 
 impl<N: AstNode> TypedNodeKey<N> {
     pub fn from_node(node: &N) -> Self {
-        let inner = NodeKey {
-            kind: node.as_any_node_ref().kind(),
-            range: node.range(),
-        };
+        let inner = NodeKey::from_node(node.as_any_node_ref());
         Self {
             inner,
             _marker: PhantomData,
@@ -312,7 +309,7 @@ struct FindNodeKeyVisitor<'a> {
     result: Option<AnyNodeRef<'a>>,
 }
 
-impl<'a> PreorderVisitor<'a> for FindNodeKeyVisitor<'a> {
+impl<'a> SourceOrderVisitor<'a> for FindNodeKeyVisitor<'a> {
     fn enter_node(&mut self, node: AnyNodeRef<'a>) -> TraversalSignal {
         if self.result.is_some() {
             return TraversalSignal::Skip;
@@ -352,6 +349,12 @@ pub struct NodeKey {
 }
 
 impl NodeKey {
+    pub fn from_node(node: AnyNodeRef) -> Self {
+        NodeKey {
+            kind: node.kind(),
+            range: node.range(),
+        }
+    }
     pub fn resolve<'a>(&self, root: AnyNodeRef<'a>) -> Option<AnyNodeRef<'a>> {
         // We need to do a binary search here. Only traverse into a node if the range is withint the node
         let mut visitor = FindNodeKeyVisitor {

crates/red_knot/src/db.rs

@@ -1,4 +1,3 @@
-use std::path::Path;
 use std::sync::Arc;
 
 pub use jars::{HasJar, HasJars};
@@ -7,12 +6,12 @@ pub use runtime::DbRuntime;
 pub use storage::JarsStorage;
 
 use crate::files::FileId;
-use crate::lint::{Diagnostics, LintSemanticStorage, LintSyntaxStorage};
-use crate::module::{Module, ModuleData, ModuleName, ModuleResolver, ModuleSearchPath};
-use crate::parse::{Parsed, ParsedStorage};
-use crate::source::{Source, SourceStorage};
-use crate::symbols::{SymbolId, SymbolTable, SymbolTablesStorage};
-use crate::types::{Type, TypeStore};
+use crate::lint::{LintSemanticStorage, LintSyntaxStorage};
+use crate::module::ModuleResolver;
+use crate::parse::ParsedStorage;
+use crate::semantic::SemanticIndexStorage;
+use crate::semantic::TypeStore;
+use crate::source::SourceStorage;
 
 mod jars;
 mod query;
@@ -61,6 +60,8 @@ pub trait ParallelDatabase: Database + Send {
     fn snapshot(&self) -> Snapshot<Self>;
 }
 
+pub trait DbWithJar<Jar>: Database + HasJar<Jar> {}
+
 /// Readonly snapshot of a database.
 ///
 /// ## Dead locks
@@ -96,45 +97,24 @@ where
     }
 }
 
+pub trait Upcast<T: ?Sized> {
+    fn upcast(&self) -> &T;
+}
+
 // Red knot specific databases code.
 
-pub trait SourceDb: Database {
+pub trait SourceDb: DbWithJar<SourceJar> {
     // queries
     fn file_id(&self, path: &std::path::Path) -> FileId;
 
     fn file_path(&self, file_id: FileId) -> Arc<std::path::Path>;
-
-    fn source(&self, file_id: FileId) -> QueryResult<Source>;
-
-    fn parse(&self, file_id: FileId) -> QueryResult<Parsed>;
 }
 
-pub trait SemanticDb: SourceDb {
-    // queries
-    fn resolve_module(&self, name: ModuleName) -> QueryResult<Option<Module>>;
+pub trait SemanticDb: SourceDb + DbWithJar<SemanticJar> + Upcast<dyn SourceDb> {}
 
-    fn file_to_module(&self, file_id: FileId) -> QueryResult<Option<Module>>;
+pub trait LintDb: SemanticDb + DbWithJar<LintJar> + Upcast<dyn SemanticDb> {}
 
-    fn path_to_module(&self, path: &Path) -> QueryResult<Option<Module>>;
-
-    fn symbol_table(&self, file_id: FileId) -> QueryResult<Arc<SymbolTable>>;
-
-    fn infer_symbol_type(&self, file_id: FileId, symbol_id: SymbolId) -> QueryResult<Type>;
-
-    // mutations
-
-    fn add_module(&mut self, path: &Path) -> Option<(Module, Vec<Arc<ModuleData>>)>;
-
-    fn set_module_search_paths(&mut self, paths: Vec<ModuleSearchPath>);
-}
-
-pub trait LintDb: SemanticDb {
-    fn lint_syntax(&self, file_id: FileId) -> QueryResult<Diagnostics>;
-
-    fn lint_semantic(&self, file_id: FileId) -> QueryResult<Diagnostics>;
-}
-
-pub trait Db: LintDb {}
+pub trait Db: LintDb + Upcast<dyn LintDb> {}
 
 #[derive(Debug, Default)]
 pub struct SourceJar {
@@ -145,7 +125,7 @@ pub struct SourceJar {
 #[derive(Debug, Default)]
 pub struct SemanticJar {
     pub module_resolver: ModuleResolver,
-    pub symbol_tables: SymbolTablesStorage,
+    pub semantic_indices: SemanticIndexStorage,
     pub type_store: TypeStore,
 }
 
@@ -161,19 +141,10 @@ pub(crate) mod tests {
     use std::sync::Arc;
 
     use crate::db::{
-        Database, DbRuntime, HasJar, HasJars, JarsStorage, LintDb, LintJar, QueryResult, SourceDb,
-        SourceJar,
+        Database, DbRuntime, DbWithJar, HasJar, HasJars, JarsStorage, LintDb, LintJar, QueryResult,
+        SourceDb, SourceJar, Upcast,
     };
     use crate::files::{FileId, Files};
-    use crate::lint::{lint_semantic, lint_syntax, Diagnostics};
-    use crate::module::{
-        add_module, file_to_module, path_to_module, resolve_module, set_module_search_paths,
-        Module, ModuleData, ModuleName, ModuleSearchPath,
-    };
-    use crate::parse::{parse, Parsed};
-    use crate::source::{source_text, Source};
-    use crate::symbols::{symbol_table, SymbolId, SymbolTable};
-    use crate::types::{infer_symbol_type, Type};
 
     use super::{SemanticDb, SemanticJar};
 
@@ -223,56 +194,36 @@ pub(crate) mod tests {
         fn file_path(&self, file_id: FileId) -> Arc<Path> {
             self.files.path(file_id)
         }
+    }
 
-        fn source(&self, file_id: FileId) -> QueryResult<Source> {
-            source_text(self, file_id)
-        }
+    impl DbWithJar<SourceJar> for TestDb {}
 
-        fn parse(&self, file_id: FileId) -> QueryResult<Parsed> {
-            parse(self, file_id)
+    impl Upcast<dyn SourceDb> for TestDb {
+        fn upcast(&self) -> &(dyn SourceDb + 'static) {
+            self
         }
     }
 
-    impl SemanticDb for TestDb {
-        fn resolve_module(&self, name: ModuleName) -> QueryResult<Option<Module>> {
-            resolve_module(self, name)
-        }
+    impl SemanticDb for TestDb {}
 
-        fn file_to_module(&self, file_id: FileId) -> QueryResult<Option<Module>> {
-            file_to_module(self, file_id)
-        }
+    impl DbWithJar<SemanticJar> for TestDb {}
 
-        fn path_to_module(&self, path: &Path) -> QueryResult<Option<Module>> {
-            path_to_module(self, path)
-        }
-
-        fn symbol_table(&self, file_id: FileId) -> QueryResult<Arc<SymbolTable>> {
-            symbol_table(self, file_id)
-        }
-
-        fn infer_symbol_type(&self, file_id: FileId, symbol_id: SymbolId) -> QueryResult<Type> {
-            infer_symbol_type(self, file_id, symbol_id)
-        }
-
-        fn add_module(&mut self, path: &Path) -> Option<(Module, Vec<Arc<ModuleData>>)> {
-            add_module(self, path)
-        }
-
-        fn set_module_search_paths(&mut self, paths: Vec<ModuleSearchPath>) {
-            set_module_search_paths(self, paths);
+    impl Upcast<dyn SemanticDb> for TestDb {
+        fn upcast(&self) -> &(dyn SemanticDb + 'static) {
+            self
         }
     }
 
-    impl LintDb for TestDb {
-        fn lint_syntax(&self, file_id: FileId) -> QueryResult<Diagnostics> {
-            lint_syntax(self, file_id)
-        }
+    impl LintDb for TestDb {}
 
-        fn lint_semantic(&self, file_id: FileId) -> QueryResult<Diagnostics> {
-            lint_semantic(self, file_id)
+    impl Upcast<dyn LintDb> for TestDb {
+        fn upcast(&self) -> &(dyn LintDb + 'static) {
+            self
         }
     }
 
+    impl DbWithJar<LintJar> for TestDb {}
+
     impl HasJars for TestDb {
         type Jars = (SourceJar, SemanticJar, LintJar);
 

crates/red_knot/src/db/jars.rs

@@ -10,7 +10,7 @@ use crate::db::query::QueryResult;
 /// `Database` trait and the jar allows to write queries in isolation without having to know how they get composed at the upper levels.
 ///
 /// Salsa further defines a `HasIngredient` trait which slices the jar to a specific storage (e.g. a specific cache).
-/// We don't need this just jet because we write our queries by hand. We may want a similar trait if we decide
+/// We don't need this just yet because we write our queries by hand. We may want a similar trait if we decide
 /// to use a macro to generate the queries.
 pub trait HasJar<T> {
     /// Gives a read-only reference to the jar.

crates/red_knot/src/files.rs

@@ -81,9 +81,7 @@ impl FilesInner {
     /// Inserts the path and returns a new id for it or returns the id if it is an existing path.
     // TODO should this accept Path or PathBuf?
     pub(crate) fn intern(&mut self, path: &Path) -> FileId {
-        let mut hasher = FxHasher::default();
-        path.hash(&mut hasher);
-        let hash = hasher.finish();
+        let hash = FilesInner::hash_path(path);
 
         let entry = self
             .by_path
@@ -94,12 +92,20 @@ impl FilesInner {
             RawEntryMut::Occupied(entry) => *entry.key(),
             RawEntryMut::Vacant(entry) => {
                 let id = self.by_id.push(Arc::from(path));
-                entry.insert_with_hasher(hash, id, (), |_| hash);
+                entry.insert_with_hasher(hash, id, (), |file| {
+                    FilesInner::hash_path(&self.by_id[*file])
+                });
                 id
             }
         }
     }
 
+    fn hash_path(path: &Path) -> u64 {
+        let mut hasher = FxHasher::default();
+        path.hash(&mut hasher);
+        hasher.finish()
+    }
+
     pub(crate) fn try_get(&self, path: &Path) -> Option<FileId> {
         let mut hasher = FxHasher::default();
         path.hash(&mut hasher);
@@ -155,4 +161,20 @@ mod tests {
         let id2 = files.intern(&path2);
         assert_ne!(id1, id2);
     }
+
+    #[test]
+    fn four_files() {
+        let files = Files::default();
+        let foo_path = PathBuf::from("foo");
+        let foo_id = files.intern(&foo_path);
+        let bar_path = PathBuf::from("bar");
+        files.intern(&bar_path);
+        let baz_path = PathBuf::from("baz");
+        files.intern(&baz_path);
+        let qux_path = PathBuf::from("qux");
+        files.intern(&qux_path);
+
+        let foo_id_2 = files.try_get(&foo_path).expect("foo_path to be found");
+        assert_eq!(foo_id_2, foo_id);
+    }
 }

crates/red_knot/src/hir.rs

@@ -1,6 +1,6 @@
 //! Key observations
 //!
-//! The HIR avoids allocations to large extends by:
+//! The HIR (High-Level Intermediate Representation) avoids allocations to large extends by:
 //! * Using an arena per node type
 //! * using ids and id ranges to reference items.
 //!

crates/red_knot/src/lib.rs

@@ -17,9 +17,9 @@ pub mod lint;
 pub mod module;
 mod parse;
 pub mod program;
+mod semantic;
 pub mod source;
-mod symbols;
-mod types;
+pub mod typeshed_versions;
 pub mod watch;
 
 pub(crate) type FxDashMap<K, V> = dashmap::DashMap<K, V, BuildHasherDefault<FxHasher>>;

crates/red_knot/src/lint.rs

@@ -5,21 +5,23 @@ use std::time::Duration;
 
 use ruff_python_ast::visitor::Visitor;
 use ruff_python_ast::{ModModule, StringLiteral};
+use ruff_python_parser::Parsed;
 
 use crate::cache::KeyValueCache;
-use crate::db::{HasJar, LintDb, LintJar, QueryResult, SemanticDb};
+use crate::db::{LintDb, LintJar, QueryResult};
 use crate::files::FileId;
-use crate::parse::Parsed;
-use crate::source::Source;
-use crate::symbols::{Definition, SymbolId, SymbolTable};
-use crate::types::Type;
+use crate::module::{resolve_module, ModuleName};
+use crate::parse::parse;
+use crate::semantic::{infer_definition_type, infer_symbol_public_type, Type};
+use crate::semantic::{
+    resolve_global_symbol, semantic_index, Definition, GlobalSymbolId, SemanticIndex, SymbolId,
+};
+use crate::source::{source_text, Source};
 
 #[tracing::instrument(level = "debug", skip(db))]
-pub(crate) fn lint_syntax<Db>(db: &Db, file_id: FileId) -> QueryResult<Diagnostics>
-where
-    Db: LintDb + HasJar<LintJar>,
-{
-    let storage = &db.jar()?.lint_syntax;
+pub(crate) fn lint_syntax(db: &dyn LintDb, file_id: FileId) -> QueryResult<Diagnostics> {
+    let lint_jar: &LintJar = db.jar()?;
+    let storage = &lint_jar.lint_syntax;
 
     #[allow(clippy::print_stdout)]
     if std::env::var("RED_KNOT_SLOW_LINT").is_ok() {
@@ -33,13 +35,13 @@ where
     storage.get(&file_id, |file_id| {
         let mut diagnostics = Vec::new();
 
-        let source = db.source(*file_id)?;
+        let source = source_text(db.upcast(), *file_id)?;
         lint_lines(source.text(), &mut diagnostics);
 
-        let parsed = db.parse(*file_id)?;
+        let parsed = parse(db.upcast(), *file_id)?;
 
         if parsed.errors().is_empty() {
-            let ast = parsed.ast();
+            let ast = parsed.syntax();
 
             let mut visitor = SyntaxLintVisitor {
                 diagnostics,
@@ -73,27 +75,26 @@ fn lint_lines(source: &str, diagnostics: &mut Vec<String>) {
 }
 
 #[tracing::instrument(level = "debug", skip(db))]
-pub(crate) fn lint_semantic<Db>(db: &Db, file_id: FileId) -> QueryResult<Diagnostics>
-where
-    Db: LintDb + HasJar<LintJar>,
-{
-    let storage = &db.jar()?.lint_semantic;
+pub(crate) fn lint_semantic(db: &dyn LintDb, file_id: FileId) -> QueryResult<Diagnostics> {
+    let lint_jar: &LintJar = db.jar()?;
+    let storage = &lint_jar.lint_semantic;
 
     storage.get(&file_id, |file_id| {
-        let source = db.source(*file_id)?;
-        let parsed = db.parse(*file_id)?;
-        let symbols = db.symbol_table(*file_id)?;
+        let source = source_text(db.upcast(), *file_id)?;
+        let parsed = parse(db.upcast(), *file_id)?;
+        let semantic_index = semantic_index(db.upcast(), *file_id)?;
 
         let context = SemanticLintContext {
             file_id: *file_id,
             source,
-            parsed,
-            symbols,
+            parsed: &parsed,
+            semantic_index,
             db,
             diagnostics: RefCell::new(Vec::new()),
         };
 
         lint_unresolved_imports(&context)?;
+        lint_bad_overrides(&context)?;
 
         Ok(Diagnostics::from(context.diagnostics.take()))
     })
@@ -101,17 +102,17 @@ where
 
 fn lint_unresolved_imports(context: &SemanticLintContext) -> QueryResult<()> {
     // TODO: Consider iterating over the dependencies (imports) only instead of all definitions.
-    for (symbol, definition) in context.symbols().all_definitions() {
+    for (symbol, definition) in context.semantic_index().symbol_table().all_definitions() {
         match definition {
             Definition::Import(import) => {
-                let ty = context.infer_symbol_type(symbol)?;
+                let ty = context.infer_symbol_public_type(symbol)?;
 
                 if ty.is_unknown() {
                     context.push_diagnostic(format!("Unresolved module {}", import.module));
                 }
             }
             Definition::ImportFrom(import) => {
-                let ty = context.infer_symbol_type(symbol)?;
+                let ty = context.infer_symbol_public_type(symbol)?;
 
                 if ty.is_unknown() {
                     let module_name = import.module().map(Deref::deref).unwrap_or_default();
@@ -140,12 +141,61 @@ fn lint_unresolved_imports(context: &SemanticLintContext) -> QueryResult<()> {
     Ok(())
 }
 
+fn lint_bad_overrides(context: &SemanticLintContext) -> QueryResult<()> {
+    // TODO we should have a special marker on the real typing module (from typeshed) so if you
+    // have your own "typing" module in your project, we don't consider it THE typing module (and
+    // same for other stdlib modules that our lint rules care about)
+    let Some(typing_override) = context.resolve_global_symbol("typing", "override")? else {
+        // TODO once we bundle typeshed, this should be unreachable!()
+        return Ok(());
+    };
+
+    // TODO we should maybe index definitions by type instead of iterating all, or else iterate all
+    // just once, match, and branch to all lint rules that care about a type of definition
+    for (symbol, definition) in context.semantic_index().symbol_table().all_definitions() {
+        if !matches!(definition, Definition::FunctionDef(_)) {
+            continue;
+        }
+        let ty = infer_definition_type(
+            context.db.upcast(),
+            GlobalSymbolId {
+                file_id: context.file_id,
+                symbol_id: symbol,
+            },
+            definition.clone(),
+        )?;
+        let Type::Function(func) = ty else {
+            unreachable!("type of a FunctionDef should always be a Function");
+        };
+        let Some(class) = func.get_containing_class(context.db.upcast())? else {
+            // not a method of a class
+            continue;
+        };
+        if func.has_decorator(context.db.upcast(), typing_override)? {
+            let method_name = func.name(context.db.upcast())?;
+            if class
+                .get_super_class_member(context.db.upcast(), &method_name)?
+                .is_none()
+            {
+                // TODO should have a qualname() method to support nested classes
+                context.push_diagnostic(
+                    format!(
+                        "Method {}.{} is decorated with `typing.override` but does not override any base class method",
+                        class.name(context.db.upcast())?,
+                        method_name,
+                    ));
+            }
+        }
+    }
+    Ok(())
+}
+
 pub struct SemanticLintContext<'a> {
     file_id: FileId,
     source: Source,
-    parsed: Parsed,
-    symbols: Arc<SymbolTable>,
-    db: &'a dyn SemanticDb,
+    parsed: &'a Parsed<ModModule>,
+    semantic_index: Arc<SemanticIndex>,
+    db: &'a dyn LintDb,
     diagnostics: RefCell<Vec<String>>,
 }
 
@@ -158,16 +208,22 @@ impl<'a> SemanticLintContext<'a> {
         self.file_id
     }
 
-    pub fn ast(&self) -> &ModModule {
-        self.parsed.ast()
+    pub fn ast(&self) -> &'a ModModule {
+        self.parsed.syntax()
     }
 
-    pub fn symbols(&self) -> &SymbolTable {
-        &self.symbols
+    pub fn semantic_index(&self) -> &SemanticIndex {
+        &self.semantic_index
     }
 
-    pub fn infer_symbol_type(&self, symbol_id: SymbolId) -> QueryResult<Type> {
-        self.db.infer_symbol_type(self.file_id, symbol_id)
+    pub fn infer_symbol_public_type(&self, symbol_id: SymbolId) -> QueryResult<Type> {
+        infer_symbol_public_type(
+            self.db.upcast(),
+            GlobalSymbolId {
+                file_id: self.file_id,
+                symbol_id,
+            },
+        )
     }
 
     pub fn push_diagnostic(&self, diagnostic: String) {
@@ -177,6 +233,18 @@ impl<'a> SemanticLintContext<'a> {
     pub fn extend_diagnostics(&mut self, diagnostics: impl IntoIterator<Item = String>) {
         self.diagnostics.get_mut().extend(diagnostics);
     }
+
+    pub fn resolve_global_symbol(
+        &self,
+        module: &str,
+        symbol_name: &str,
+    ) -> QueryResult<Option<GlobalSymbolId>> {
+        let Some(module) = resolve_module(self.db.upcast(), ModuleName::new(module))? else {
+            return Ok(None);
+        };
+
+        resolve_global_symbol(self.db.upcast(), module, symbol_name)
+    }
 }
 
 #[derive(Debug)]

crates/red_knot/src/main.rs

@@ -11,8 +11,8 @@ use tracing_subscriber::layer::{Context, Filter, SubscriberExt};
 use tracing_subscriber::{Layer, Registry};
 use tracing_tree::time::Uptime;
 
-use red_knot::db::{HasJar, ParallelDatabase, QueryError, SemanticDb, SourceDb, SourceJar};
-use red_knot::module::{ModuleSearchPath, ModuleSearchPathKind};
+use red_knot::db::{HasJar, ParallelDatabase, QueryError, SourceDb, SourceJar};
+use red_knot::module::{set_module_search_paths, ModuleResolutionInputs};
 use red_knot::program::check::ExecutionMode;
 use red_knot::program::{FileWatcherChange, Program};
 use red_knot::watch::FileWatcher;
@@ -44,12 +44,17 @@ fn main() -> anyhow::Result<()> {
     let workspace_folder = entry_point.parent().unwrap();
     let workspace = Workspace::new(workspace_folder.to_path_buf());
 
-    let workspace_search_path = ModuleSearchPath::new(
-        workspace.root().to_path_buf(),
-        ModuleSearchPathKind::FirstParty,
-    );
+    let workspace_search_path = workspace.root().to_path_buf();
+
+    let search_paths = ModuleResolutionInputs {
+        extra_paths: vec![],
+        workspace_root: workspace_search_path,
+        site_packages: None,
+        custom_typeshed: None,
+    };
+
     let mut program = Program::new(workspace);
-    program.set_module_search_paths(vec![workspace_search_path]);
+    set_module_search_paths(&mut program, search_paths);
 
     let entry_id = program.file_id(entry_point);
     program.workspace_mut().open_file(entry_id);

crates/red_knot/src/module.rs

@@ -7,51 +7,58 @@ use std::sync::Arc;
 use dashmap::mapref::entry::Entry;
 use smol_str::SmolStr;
 
-use crate::db::{HasJar, QueryResult, SemanticDb, SemanticJar};
+use crate::db::{QueryResult, SemanticDb, SemanticJar};
 use crate::files::FileId;
-use crate::symbols::Dependency;
+use crate::semantic::Dependency;
 use crate::FxDashMap;
 
-/// ID uniquely identifying a module.
+/// Representation of a Python module.
+///
+/// The inner type wrapped by this struct is a unique identifier for the module
+/// that is used by the struct's methods to lazily query information about the module.
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 pub struct Module(u32);
 
 impl Module {
-    pub fn name<Db>(&self, db: &Db) -> QueryResult<ModuleName>
-    where
-        Db: HasJar<SemanticJar>,
-    {
-        let modules = &db.jar()?.module_resolver;
+    /// Return the absolute name of the module (e.g. `foo.bar`)
+    pub fn name(&self, db: &dyn SemanticDb) -> QueryResult<ModuleName> {
+        let jar: &SemanticJar = db.jar()?;
+        let modules = &jar.module_resolver;
 
         Ok(modules.modules.get(self).unwrap().name.clone())
     }
 
-    pub fn path<Db>(&self, db: &Db) -> QueryResult<ModulePath>
-    where
-        Db: HasJar<SemanticJar>,
-    {
-        let modules = &db.jar()?.module_resolver;
+    /// Return the path to the source code that defines this module
+    pub fn path(&self, db: &dyn SemanticDb) -> QueryResult<ModulePath> {
+        let jar: &SemanticJar = db.jar()?;
+        let modules = &jar.module_resolver;
 
         Ok(modules.modules.get(self).unwrap().path.clone())
     }
 
-    pub fn kind<Db>(&self, db: &Db) -> QueryResult<ModuleKind>
-    where
-        Db: HasJar<SemanticJar>,
-    {
-        let modules = &db.jar()?.module_resolver;
+    /// Determine whether this module is a single-file module or a package
+    pub fn kind(&self, db: &dyn SemanticDb) -> QueryResult<ModuleKind> {
+        let jar: &SemanticJar = db.jar()?;
+        let modules = &jar.module_resolver;
 
         Ok(modules.modules.get(self).unwrap().kind)
     }
 
-    pub fn resolve_dependency<Db>(
+    /// Attempt to resolve a dependency of this module to an absolute [`ModuleName`].
+    ///
+    /// A dependency could be either absolute (e.g. the `foo` dependency implied by `from foo import bar`)
+    /// or relative to this module (e.g. the `.foo` dependency implied by `from .foo import bar`)
+    ///
+    /// - Returns an error if the query failed.
+    /// - Returns `Ok(None)` if the query succeeded,
+    ///   but the dependency refers to a module that does not exist.
+    /// - Returns `Ok(Some(ModuleName))` if the query succeeded,
+    ///   and the dependency refers to a module that exists.
+    pub fn resolve_dependency(
         &self,
-        db: &Db,
+        db: &dyn SemanticDb,
         dependency: &Dependency,
-    ) -> QueryResult<Option<ModuleName>>
-    where
-        Db: HasJar<SemanticJar>,
-    {
+    ) -> QueryResult<Option<ModuleName>> {
         let (level, module) = match dependency {
             Dependency::Module(module) => return Ok(Some(module.clone())),
             Dependency::Relative { level, module } => (*level, module.as_deref()),
@@ -96,7 +103,8 @@ impl Module {
 
 /// A module name, e.g. `foo.bar`.
 ///
-/// Always normalized to the absolute form (never a relative module name).
+/// Always normalized to the absolute form
+/// (never a relative module name, i.e., never `.foo`).
 #[derive(Clone, Debug, Eq, PartialEq, Hash)]
 pub struct ModuleName(smol_str::SmolStr);
 
@@ -133,10 +141,13 @@ impl ModuleName {
         Some(Self(name))
     }
 
+    /// An iterator over the components of the module name:
+    /// `foo.bar.baz` -> `foo`, `bar`, `baz`
     pub fn components(&self) -> impl DoubleEndedIterator<Item = &str> {
         self.0.split('.')
     }
 
+    /// The name of this module's immediate parent, if it has a parent
     pub fn parent(&self) -> Option<ModuleName> {
         let (_, parent) = self.0.rsplit_once('.')?;
 
@@ -168,9 +179,10 @@ impl std::fmt::Display for ModuleName {
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 pub enum ModuleKind {
+    /// A single-file module (e.g. `foo.py` or `foo.pyi`)
     Module,
 
-    /// A python package (a `__init__.py` or `__init__.pyi` file)
+    /// A python package (`foo/__init__.py` or `foo/__init__.pyi`)
     Package,
 }
 
@@ -190,10 +202,12 @@ impl ModuleSearchPath {
         }
     }
 
+    /// Determine whether this is a first-party, third-party or standard-library search path
     pub fn kind(&self) -> ModuleSearchPathKind {
         self.inner.kind
     }
 
+    /// Return the location of the search path on the file system
     pub fn path(&self) -> &Path {
         &self.inner.path
     }
@@ -211,22 +225,31 @@ struct ModuleSearchPathInner {
     kind: ModuleSearchPathKind,
 }
 
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+/// Enumeration of the different kinds of search paths type checkers are expected to support.
+///
+/// N.B. Although we don't implement `Ord` for this enum, they are ordered in terms of the
+/// priority that we want to give these modules when resolving them.
+/// This is roughly [the order given in the typing spec], but typeshed's stubs
+/// for the standard library are moved higher up to match Python's semantics at runtime.
+///
+/// [the order given in the typing spec]: https://typing.readthedocs.io/en/latest/spec/distributing.html#import-resolution-ordering
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, is_macro::Is)]
 pub enum ModuleSearchPathKind {
-    // Project dependency
+    /// "Extra" paths provided by the user in a config file, env var or CLI flag.
+    /// E.g. mypy's `MYPYPATH` env var, or pyright's `stubPath` configuration setting
+    Extra,
+
+    /// Files in the project we're directly being invoked on
     FirstParty,
 
-    // e.g. site packages
-    ThirdParty,
-
-    // e.g. built-in modules, typeshed
+    /// The `stdlib` directory of typeshed (either vendored or custom)
     StandardLibrary,
-}
 
-impl ModuleSearchPathKind {
-    pub const fn is_first_party(self) -> bool {
-        matches!(self, Self::FirstParty)
-    }
+    /// Stubs or runtime modules installed in site-packages
+    SitePackagesThirdParty,
+
+    /// Vendored third-party stubs from typeshed
+    VendoredThirdParty,
 }
 
 #[derive(Debug, Eq, PartialEq)]
@@ -240,16 +263,15 @@ pub struct ModuleData {
 // Queries
 //////////////////////////////////////////////////////
 
-/// Resolves a module name to a module id
-/// TODO: This would not work with Salsa because `ModuleName` isn't an ingredient and, therefore, cannot be used as part of a query.
-///  For this to work with salsa, it would be necessary to intern all `ModuleName`s.
+/// Resolves a module name to a module.
+///
+/// TODO: This would not work with Salsa because `ModuleName` isn't an ingredient
+/// and, therefore, cannot be used as part of a query.
+/// For this to work with salsa, it would be necessary to intern all `ModuleName`s.
 #[tracing::instrument(level = "debug", skip(db))]
-pub fn resolve_module<Db>(db: &Db, name: ModuleName) -> QueryResult<Option<Module>>
-where
-    Db: SemanticDb + HasJar<SemanticJar>,
-{
-    let jar = db.jar();
-    let modules = &jar?.module_resolver;
+pub fn resolve_module(db: &dyn SemanticDb, name: ModuleName) -> QueryResult<Option<Module>> {
+    let jar: &SemanticJar = db.jar()?;
+    let modules = &jar.module_resolver;
 
     let entry = modules.by_name.entry(name.clone());
 
@@ -267,7 +289,7 @@ where
             let file_id = db.file_id(&normalized);
             let path = ModulePath::new(root_path.clone(), file_id);
 
-            let id = Module(
+            let module = Module(
                 modules
                     .next_module_id
                     .fetch_add(1, std::sync::atomic::Ordering::Relaxed),
@@ -275,7 +297,7 @@ where
 
             modules
                 .modules
-                .insert(id, Arc::from(ModuleData { name, path, kind }));
+                .insert(module, Arc::from(ModuleData { name, path, kind }));
 
             // A path can map to multiple modules because of symlinks:
             // ```
@@ -284,42 +306,36 @@ where
             // ```
             // Here, both `foo` and `bar` resolve to the same module but through different paths.
             // That's why we need to insert the absolute path and not the normalized path here.
-            let absolute_id = if absolute_path == normalized {
+            let absolute_file_id = if absolute_path == normalized {
                 file_id
             } else {
                 db.file_id(&absolute_path)
             };
 
-            modules.by_file.insert(absolute_id, id);
+            modules.by_file.insert(absolute_file_id, module);
 
-            entry.insert_entry(id);
+            entry.insert_entry(module);
 
-            Ok(Some(id))
+            Ok(Some(module))
         }
     }
 }
 
-/// Resolves the module id for the given path.
+/// Resolves the module for the given path.
 ///
-/// Returns `None` if the path is not a module in `sys.path`.
+/// Returns `None` if the path is not a module locatable via `sys.path`.
 #[tracing::instrument(level = "debug", skip(db))]
-pub fn path_to_module<Db>(db: &Db, path: &Path) -> QueryResult<Option<Module>>
-where
-    Db: SemanticDb + HasJar<SemanticJar>,
-{
+pub fn path_to_module(db: &dyn SemanticDb, path: &Path) -> QueryResult<Option<Module>> {
     let file = db.file_id(path);
     file_to_module(db, file)
 }
 
-/// Resolves the module id for the file with the given id.
+/// Resolves the module for the file with the given id.
 ///
-/// Returns `None` if the file is not a module in `sys.path`.
+/// Returns `None` if the file is not a module locatable via `sys.path`.
 #[tracing::instrument(level = "debug", skip(db))]
-pub fn file_to_module<Db>(db: &Db, file: FileId) -> QueryResult<Option<Module>>
-where
-    Db: SemanticDb + HasJar<SemanticJar>,
-{
-    let jar = db.jar()?;
+pub fn file_to_module(db: &dyn SemanticDb, file: FileId) -> QueryResult<Option<Module>> {
+    let jar: &SemanticJar = db.jar()?;
     let modules = &jar.module_resolver;
 
     if let Some(existing) = modules.by_file.get(&file) {
@@ -343,12 +359,12 @@ where
 
     // Resolve the module name to see if Python would resolve the name to the same path.
     // If it doesn't, then that means that multiple modules have the same in different
-    // root paths, but that the module corresponding to the past path is in a lower priority path,
+    // root paths, but that the module corresponding to the past path is in a lower priority search path,
     // in which case we ignore it.
-    let Some(module_id) = resolve_module(db, module_name)? else {
+    let Some(module) = resolve_module(db, module_name)? else {
         return Ok(None);
     };
-    let module_path = module_id.path(db)?;
+    let module_path = module.path(db)?;
 
     if module_path.root() == &root_path {
         let Ok(normalized) = path.canonicalize() else {
@@ -368,7 +384,7 @@ where
         }
 
         // Path has been inserted by `resolved`
-        Ok(Some(module_id))
+        Ok(Some(module))
     } else {
         // This path is for a module with the same name but in a module search path with a lower priority.
         // Ignore it.
@@ -381,31 +397,100 @@ where
 //////////////////////////////////////////////////////
 
 /// Changes the module search paths to `search_paths`.
-pub fn set_module_search_paths<Db>(db: &mut Db, search_paths: Vec<ModuleSearchPath>)
-where
-    Db: SemanticDb + HasJar<SemanticJar>,
-{
-    let jar = db.jar_mut();
+pub fn set_module_search_paths(db: &mut dyn SemanticDb, search_paths: ModuleResolutionInputs) {
+    let jar: &mut SemanticJar = db.jar_mut();
 
-    jar.module_resolver = ModuleResolver::new(search_paths);
+    jar.module_resolver = ModuleResolver::new(search_paths.into_ordered_search_paths());
 }
 
-/// Adds a module to the resolver.
+/// Struct for holding the various paths that are put together
+/// to create an `OrderedSearchPatsh` instance
+///
+/// - `extra_paths` is a list of user-provided paths
+///   that should take first priority in the module resolution.
+///   Examples in other type checkers are mypy's MYPYPATH environment variable,
+///   or pyright's stubPath configuration setting.
+/// - `workspace_root` is the root of the workspace,
+///   used for finding first-party modules
+/// - `site-packages` is the path to the user's `site-packages` directory,
+///   where third-party packages from ``PyPI`` are installed
+/// - `custom_typeshed` is a path to standard-library typeshed stubs.
+///   Currently this has to be a directory that exists on disk.
+///   (TODO: fall back to vendored stubs if no custom directory is provided.)
+#[derive(Debug)]
+pub struct ModuleResolutionInputs {
+    pub extra_paths: Vec<PathBuf>,
+    pub workspace_root: PathBuf,
+    pub site_packages: Option<PathBuf>,
+    pub custom_typeshed: Option<PathBuf>,
+}
+
+impl ModuleResolutionInputs {
+    /// Implementation of PEP 561's module resolution order
+    /// (with some small, deliberate, differences)
+    fn into_ordered_search_paths(self) -> OrderedSearchPaths {
+        let ModuleResolutionInputs {
+            extra_paths,
+            workspace_root,
+            site_packages,
+            custom_typeshed,
+        } = self;
+
+        OrderedSearchPaths(
+            extra_paths
+                .into_iter()
+                .map(|path| ModuleSearchPath::new(path, ModuleSearchPathKind::Extra))
+                .chain(std::iter::once(ModuleSearchPath::new(
+                    workspace_root,
+                    ModuleSearchPathKind::FirstParty,
+                )))
+                // TODO fallback to vendored typeshed stubs if no custom typeshed directory is provided by the user
+                .chain(custom_typeshed.into_iter().map(|path| {
+                    ModuleSearchPath::new(
+                        path.join(TYPESHED_STDLIB_DIRECTORY),
+                        ModuleSearchPathKind::StandardLibrary,
+                    )
+                }))
+                .chain(site_packages.into_iter().map(|path| {
+                    ModuleSearchPath::new(path, ModuleSearchPathKind::SitePackagesThirdParty)
+                }))
+                // TODO vendor typeshed's third-party stubs as well as the stdlib and fallback to them as a final step
+                .collect(),
+        )
+    }
+}
+
+const TYPESHED_STDLIB_DIRECTORY: &str = "stdlib";
+
+/// A resolved module resolution order, implementing PEP 561
+/// (with some small, deliberate differences)
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+struct OrderedSearchPaths(Vec<ModuleSearchPath>);
+
+impl Deref for OrderedSearchPaths {
+    type Target = [ModuleSearchPath];
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+/// Adds a module located at `path` to the resolver.
 ///
 /// Returns `None` if the path doesn't resolve to a module.
 ///
-/// Returns `Some` with the id of the module and the ids of the modules that need re-resolving
-/// because they were part of a namespace package and might now resolve differently.
+/// Returns `Some(module, other_modules)`, where `module` is the resolved module
+/// with file location `path`, and `other_modules` is a `Vec` of `ModuleData` instances.
+/// Each element in `other_modules` provides information regarding a single module that needs
+/// re-resolving because it was part of a namespace package and might now resolve differently.
+///
 /// Note: This won't work with salsa because `Path` is not an ingredient.
-pub fn add_module<Db>(db: &mut Db, path: &Path) -> Option<(Module, Vec<Arc<ModuleData>>)>
-where
-    Db: SemanticDb + HasJar<SemanticJar>,
-{
+pub fn add_module(db: &mut dyn SemanticDb, path: &Path) -> Option<(Module, Vec<Arc<ModuleData>>)> {
     // No locking is required because we're holding a mutable reference to `modules`.
 
     // TODO This needs tests
 
-    // Note: Intentionally by-pass caching here. Module should not be in the cache yet.
+    // Note: Intentionally bypass caching here. Module should not be in the cache yet.
     let module = path_to_module(db, path).ok()??;
 
     // The code below is to handle the addition of `__init__.py` files.
@@ -426,18 +511,18 @@ where
 
     let mut to_remove = Vec::new();
 
-    let jar = db.jar_mut();
+    let jar: &mut SemanticJar = db.jar_mut();
     let modules = &mut jar.module_resolver;
 
-    modules.by_file.retain(|_, id| {
+    modules.by_file.retain(|_, module| {
         if modules
             .modules
-            .get(id)
+            .get(module)
             .unwrap()
             .name
             .starts_with(&parent_name)
         {
-            to_remove.push(*id);
+            to_remove.push(*module);
             false
         } else {
             true
@@ -446,8 +531,8 @@ where
 
     // TODO remove need for this vec
     let mut removed = Vec::with_capacity(to_remove.len());
-    for id in &to_remove {
-        removed.push(modules.remove_module_by_id(*id));
+    for module in &to_remove {
+        removed.push(modules.remove_module(*module));
     }
 
     Some((module, removed))
@@ -456,14 +541,14 @@ where
 #[derive(Default)]
 pub struct ModuleResolver {
     /// The search paths where modules are located (and searched). Corresponds to `sys.path` at runtime.
-    search_paths: Vec<ModuleSearchPath>,
+    search_paths: OrderedSearchPaths,
 
     // Locking: Locking is done by acquiring a (write) lock on `by_name`. This is because `by_name` is the primary
     // lookup method. Acquiring locks in any other ordering can result in deadlocks.
-    /// Resolves a module name to it's module id.
+    /// Looks up a module by name
     by_name: FxDashMap<ModuleName, Module>,
 
-    /// All known modules, indexed by the module id.
+    /// A map of all known modules to data about those modules
     modules: FxDashMap<Module, Arc<ModuleData>>,
 
     /// Lookup from absolute path to module.
@@ -473,7 +558,7 @@ pub struct ModuleResolver {
 }
 
 impl ModuleResolver {
-    pub fn new(search_paths: Vec<ModuleSearchPath>) -> Self {
+    fn new(search_paths: OrderedSearchPaths) -> Self {
         Self {
             search_paths,
             modules: FxDashMap::default(),
@@ -483,24 +568,27 @@ impl ModuleResolver {
         }
     }
 
-    pub(crate) fn remove_module(&mut self, file_id: FileId) {
+    /// Remove a module from the inner cache
+    pub(crate) fn remove_module_by_file(&mut self, file_id: FileId) {
         // No locking is required because we're holding a mutable reference to `self`.
-        let Some((_, id)) = self.by_file.remove(&file_id) else {
+        let Some((_, module)) = self.by_file.remove(&file_id) else {
             return;
         };
 
-        self.remove_module_by_id(id);
+        self.remove_module(module);
     }
 
-    fn remove_module_by_id(&mut self, id: Module) -> Arc<ModuleData> {
-        let (_, module) = self.modules.remove(&id).unwrap();
+    fn remove_module(&mut self, module: Module) -> Arc<ModuleData> {
+        let (_, module_data) = self.modules.remove(&module).unwrap();
 
-        self.by_name.remove(&module.name).unwrap();
+        self.by_name.remove(&module_data.name).unwrap();
 
-        // It's possible that multiple paths map to the same id. Search all other paths referencing the same module id.
-        self.by_file.retain(|_, current_id| *current_id != id);
+        // It's possible that multiple paths map to the same module.
+        // Search all other paths referencing the same module.
+        self.by_file
+            .retain(|_, current_module| *current_module != module);
 
-        module
+        module_data
     }
 }
 
@@ -529,15 +617,19 @@ impl ModulePath {
         Self { root, file_id }
     }
 
+    /// The search path that was used to locate the module
     pub fn root(&self) -> &ModuleSearchPath {
         &self.root
     }
 
+    /// The file containing the source code for the module
     pub fn file(&self) -> FileId {
         self.file_id
     }
 }
 
+/// Given a module name and a list of search paths in which to lookup modules,
+/// attempt to resolve the module name
 fn resolve_name(
     name: &ModuleName,
     search_paths: &[ModuleSearchPath],
@@ -659,7 +751,9 @@ enum PackageKind {
     /// A root package or module. E.g. `foo` in `foo.bar.baz` or just `foo`.
     Root,
 
-    /// A regular sub-package where the parent contains an `__init__.py`. For example `bar` in `foo.bar` when the `foo` directory contains an `__init__.py`.
+    /// A regular sub-package where the parent contains an `__init__.py`.
+    ///
+    /// For example, `bar` in `foo.bar` when the `foo` directory contains an `__init__.py`.
     Regular,
 
     /// A sub-package in a namespace package. A namespace package is a package without an `__init__.py`.
@@ -676,18 +770,27 @@ impl PackageKind {
 
 #[cfg(test)]
 mod tests {
-    use crate::db::tests::TestDb;
-    use crate::db::{SemanticDb, SourceDb};
-    use crate::module::{ModuleKind, ModuleName, ModuleSearchPath, ModuleSearchPathKind};
-    use crate::symbols::Dependency;
+    use std::io::{Cursor, Read};
     use std::num::NonZeroU32;
+    use std::path::{Path, PathBuf};
+
+    use zip::ZipArchive;
+
+    use crate::db::tests::TestDb;
+    use crate::db::SourceDb;
+    use crate::module::{
+        path_to_module, resolve_module, set_module_search_paths, ModuleKind, ModuleName,
+        ModuleResolutionInputs, TYPESHED_STDLIB_DIRECTORY,
+    };
+    use crate::semantic::Dependency;
 
     struct TestCase {
         temp_dir: tempfile::TempDir,
         db: TestDb,
 
-        src: ModuleSearchPath,
-        site_packages: ModuleSearchPath,
+        src: PathBuf,
+        custom_typeshed: PathBuf,
+        site_packages: PathBuf,
     }
 
     fn create_resolver() -> std::io::Result<TestCase> {
@@ -695,25 +798,31 @@ mod tests {
 
         let src = temp_dir.path().join("src");
         let site_packages = temp_dir.path().join("site_packages");
+        let custom_typeshed = temp_dir.path().join("typeshed");
 
         std::fs::create_dir(&src)?;
         std::fs::create_dir(&site_packages)?;
+        std::fs::create_dir(&custom_typeshed)?;
 
-        let src = ModuleSearchPath::new(src.canonicalize()?, ModuleSearchPathKind::FirstParty);
-        let site_packages = ModuleSearchPath::new(
-            site_packages.canonicalize()?,
-            ModuleSearchPathKind::ThirdParty,
-        );
+        let src = src.canonicalize()?;
+        let site_packages = site_packages.canonicalize()?;
+        let custom_typeshed = custom_typeshed.canonicalize()?;
 
-        let roots = vec![src.clone(), site_packages.clone()];
+        let search_paths = ModuleResolutionInputs {
+            extra_paths: vec![],
+            workspace_root: src.clone(),
+            site_packages: Some(site_packages.clone()),
+            custom_typeshed: Some(custom_typeshed.clone()),
+        };
 
         let mut db = TestDb::default();
-        db.set_module_search_paths(roots);
+        set_module_search_paths(&mut db, search_paths);
 
         Ok(TestCase {
             temp_dir,
             db,
             src,
+            custom_typeshed,
             site_packages,
         })
     }
@@ -727,23 +836,118 @@ mod tests {
             ..
         } = create_resolver()?;
 
-        let foo_path = src.path().join("foo.py");
+        let foo_path = src.join("foo.py");
         std::fs::write(&foo_path, "print('Hello, world!')")?;
 
-        let foo_module = db.resolve_module(ModuleName::new("foo"))?.unwrap();
+        let foo_module = resolve_module(&db, ModuleName::new("foo"))?.unwrap();
 
-        assert_eq!(Some(foo_module), db.resolve_module(ModuleName::new("foo"))?);
+        assert_eq!(
+            Some(foo_module),
+            resolve_module(&db, ModuleName::new("foo"))?
+        );
 
         assert_eq!(ModuleName::new("foo"), foo_module.name(&db)?);
-        assert_eq!(&src, foo_module.path(&db)?.root());
+        assert_eq!(&src, foo_module.path(&db)?.root().path());
         assert_eq!(ModuleKind::Module, foo_module.kind(&db)?);
         assert_eq!(&foo_path, &*db.file_path(foo_module.path(&db)?.file()));
 
-        assert_eq!(Some(foo_module), db.path_to_module(&foo_path)?);
+        assert_eq!(Some(foo_module), path_to_module(&db, &foo_path)?);
 
         Ok(())
     }
 
+    #[test]
+    fn stdlib() -> anyhow::Result<()> {
+        let TestCase {
+            db,
+            custom_typeshed,
+            ..
+        } = create_resolver()?;
+        let stdlib_dir = custom_typeshed.join(TYPESHED_STDLIB_DIRECTORY);
+        std::fs::create_dir_all(&stdlib_dir).unwrap();
+        let functools_path = stdlib_dir.join("functools.py");
+        std::fs::write(&functools_path, "def update_wrapper(): ...").unwrap();
+        let functools_module = resolve_module(&db, ModuleName::new("functools"))?.unwrap();
+
+        assert_eq!(
+            Some(functools_module),
+            resolve_module(&db, ModuleName::new("functools"))?
+        );
+        assert_eq!(&stdlib_dir, functools_module.path(&db)?.root().path());
+        assert_eq!(ModuleKind::Module, functools_module.kind(&db)?);
+        assert_eq!(
+            &functools_path,
+            &*db.file_path(functools_module.path(&db)?.file())
+        );
+
+        assert_eq!(
+            Some(functools_module),
+            path_to_module(&db, &functools_path)?
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn first_party_precedence_over_stdlib() -> anyhow::Result<()> {
+        let TestCase {
+            db,
+            src,
+            custom_typeshed,
+            ..
+        } = create_resolver()?;
+
+        let stdlib_dir = custom_typeshed.join(TYPESHED_STDLIB_DIRECTORY);
+        std::fs::create_dir_all(&stdlib_dir).unwrap();
+        std::fs::create_dir_all(&src).unwrap();
+
+        let stdlib_functools_path = stdlib_dir.join("functools.py");
+        let first_party_functools_path = src.join("functools.py");
+        std::fs::write(stdlib_functools_path, "def update_wrapper(): ...").unwrap();
+        std::fs::write(&first_party_functools_path, "def update_wrapper(): ...").unwrap();
+        let functools_module = resolve_module(&db, ModuleName::new("functools"))?.unwrap();
+
+        assert_eq!(
+            Some(functools_module),
+            resolve_module(&db, ModuleName::new("functools"))?
+        );
+        assert_eq!(&src, functools_module.path(&db).unwrap().root().path());
+        assert_eq!(ModuleKind::Module, functools_module.kind(&db)?);
+        assert_eq!(
+            &first_party_functools_path,
+            &*db.file_path(functools_module.path(&db)?.file())
+        );
+
+        assert_eq!(
+            Some(functools_module),
+            path_to_module(&db, &first_party_functools_path)?
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn typeshed_zip_created_at_build_time() -> anyhow::Result<()> {
+        // The file path here is hardcoded in this crate's `build.rs` script.
+        // Luckily this crate will fail to build if this file isn't available at build time.
+        const TYPESHED_ZIP_BYTES: &[u8] =
+            include_bytes!(concat!(env!("OUT_DIR"), "/zipped_typeshed.zip"));
+        assert!(!TYPESHED_ZIP_BYTES.is_empty());
+        let mut typeshed_zip_archive = ZipArchive::new(Cursor::new(TYPESHED_ZIP_BYTES))?;
+
+        let path_to_functools = Path::new("stdlib").join("functools.pyi");
+        let mut functools_module_stub = typeshed_zip_archive
+            .by_name(path_to_functools.to_str().unwrap())
+            .unwrap();
+        assert!(functools_module_stub.is_file());
+
+        let mut functools_module_stub_source = String::new();
+        functools_module_stub.read_to_string(&mut functools_module_stub_source)?;
+
+        assert!(functools_module_stub_source.contains("def update_wrapper("));
+        Ok(())
+    }
+
     #[test]
     fn resolve_package() -> anyhow::Result<()> {
         let TestCase {
@@ -753,21 +957,21 @@ mod tests {
             ..
         } = create_resolver()?;
 
-        let foo_dir = src.path().join("foo");
+        let foo_dir = src.join("foo");
         let foo_path = foo_dir.join("__init__.py");
         std::fs::create_dir(&foo_dir)?;
         std::fs::write(&foo_path, "print('Hello, world!')")?;
 
-        let foo_module = db.resolve_module(ModuleName::new("foo"))?.unwrap();
+        let foo_module = resolve_module(&db, ModuleName::new("foo"))?.unwrap();
 
         assert_eq!(ModuleName::new("foo"), foo_module.name(&db)?);
-        assert_eq!(&src, foo_module.path(&db)?.root());
+        assert_eq!(&src, foo_module.path(&db)?.root().path());
         assert_eq!(&foo_path, &*db.file_path(foo_module.path(&db)?.file()));
 
-        assert_eq!(Some(foo_module), db.path_to_module(&foo_path)?);
+        assert_eq!(Some(foo_module), path_to_module(&db, &foo_path)?);
 
         // Resolving by directory doesn't resolve to the init file.
-        assert_eq!(None, db.path_to_module(&foo_dir)?);
+        assert_eq!(None, path_to_module(&db, &foo_dir)?);
 
         Ok(())
     }
@@ -781,22 +985,22 @@ mod tests {
             ..
         } = create_resolver()?;
 
-        let foo_dir = src.path().join("foo");
+        let foo_dir = src.join("foo");
         let foo_init = foo_dir.join("__init__.py");
         std::fs::create_dir(&foo_dir)?;
         std::fs::write(&foo_init, "print('Hello, world!')")?;
 
-        let foo_py = src.path().join("foo.py");
+        let foo_py = src.join("foo.py");
         std::fs::write(&foo_py, "print('Hello, world!')")?;
 
-        let foo_module = db.resolve_module(ModuleName::new("foo"))?.unwrap();
+        let foo_module = resolve_module(&db, ModuleName::new("foo"))?.unwrap();
 
-        assert_eq!(&src, foo_module.path(&db)?.root());
+        assert_eq!(&src, foo_module.path(&db)?.root().path());
         assert_eq!(&foo_init, &*db.file_path(foo_module.path(&db)?.file()));
         assert_eq!(ModuleKind::Package, foo_module.kind(&db)?);
 
-        assert_eq!(Some(foo_module), db.path_to_module(&foo_init)?);
-        assert_eq!(None, db.path_to_module(&foo_py)?);
+        assert_eq!(Some(foo_module), path_to_module(&db, &foo_init)?);
+        assert_eq!(None, path_to_module(&db, &foo_py)?);
 
         Ok(())
     }
@@ -810,18 +1014,18 @@ mod tests {
             ..
         } = create_resolver()?;
 
-        let foo_stub = src.path().join("foo.pyi");
-        let foo_py = src.path().join("foo.py");
+        let foo_stub = src.join("foo.pyi");
+        let foo_py = src.join("foo.py");
         std::fs::write(&foo_stub, "x: int")?;
         std::fs::write(&foo_py, "print('Hello, world!')")?;
 
-        let foo = db.resolve_module(ModuleName::new("foo"))?.unwrap();
+        let foo = resolve_module(&db, ModuleName::new("foo"))?.unwrap();
 
-        assert_eq!(&src, foo.path(&db)?.root());
+        assert_eq!(&src, foo.path(&db)?.root().path());
         assert_eq!(&foo_stub, &*db.file_path(foo.path(&db)?.file()));
 
-        assert_eq!(Some(foo), db.path_to_module(&foo_stub)?);
-        assert_eq!(None, db.path_to_module(&foo_py)?);
+        assert_eq!(Some(foo), path_to_module(&db, &foo_stub)?);
+        assert_eq!(None, path_to_module(&db, &foo_py)?);
 
         Ok(())
     }
@@ -835,7 +1039,7 @@ mod tests {
             ..
         } = create_resolver()?;
 
-        let foo = src.path().join("foo");
+        let foo = src.join("foo");
         let bar = foo.join("bar");
         let baz = bar.join("baz.py");
 
@@ -844,12 +1048,12 @@ mod tests {
         std::fs::write(bar.join("__init__.py"), "")?;
         std::fs::write(&baz, "print('Hello, world!')")?;
 
-        let baz_module = db.resolve_module(ModuleName::new("foo.bar.baz"))?.unwrap();
+        let baz_module = resolve_module(&db, ModuleName::new("foo.bar.baz"))?.unwrap();
 
-        assert_eq!(&src, baz_module.path(&db)?.root());
+        assert_eq!(&src, baz_module.path(&db)?.root().path());
         assert_eq!(&baz, &*db.file_path(baz_module.path(&db)?.file()));
 
-        assert_eq!(Some(baz_module), db.path_to_module(&baz)?);
+        assert_eq!(Some(baz_module), path_to_module(&db, &baz)?);
 
         Ok(())
     }
@@ -861,6 +1065,7 @@ mod tests {
             temp_dir: _,
             src,
             site_packages,
+            ..
         } = create_resolver()?;
 
         // From [PEP420](https://peps.python.org/pep-0420/#nested-namespace-packages).
@@ -876,30 +1081,26 @@ mod tests {
         //       two.py
         // ```
 
-        let parent1 = src.path().join("parent");
+        let parent1 = src.join("parent");
         let child1 = parent1.join("child");
         let one = child1.join("one.py");
 
         std::fs::create_dir_all(child1)?;
         std::fs::write(&one, "print('Hello, world!')")?;
 
-        let parent2 = site_packages.path().join("parent");
+        let parent2 = site_packages.join("parent");
         let child2 = parent2.join("child");
         let two = child2.join("two.py");
 
         std::fs::create_dir_all(&child2)?;
         std::fs::write(&two, "print('Hello, world!')")?;
 
-        let one_module = db
-            .resolve_module(ModuleName::new("parent.child.one"))?
-            .unwrap();
+        let one_module = resolve_module(&db, ModuleName::new("parent.child.one"))?.unwrap();
 
-        assert_eq!(Some(one_module), db.path_to_module(&one)?);
+        assert_eq!(Some(one_module), path_to_module(&db, &one)?);
 
-        let two_module = db
-            .resolve_module(ModuleName::new("parent.child.two"))?
-            .unwrap();
-        assert_eq!(Some(two_module), db.path_to_module(&two)?);
+        let two_module = resolve_module(&db, ModuleName::new("parent.child.two"))?.unwrap();
+        assert_eq!(Some(two_module), path_to_module(&db, &two)?);
 
         Ok(())
     }
@@ -911,6 +1112,7 @@ mod tests {
             temp_dir: _,
             src,
             site_packages,
+            ..
         } = create_resolver()?;
 
         // Adopted test case from the [PEP420 examples](https://peps.python.org/pep-0420/#nested-namespace-packages).
@@ -926,7 +1128,7 @@ mod tests {
         //       two.py
         // ```
 
-        let parent1 = src.path().join("parent");
+        let parent1 = src.join("parent");
         let child1 = parent1.join("child");
         let one = child1.join("one.py");
 
@@ -934,22 +1136,20 @@ mod tests {
         std::fs::write(child1.join("__init__.py"), "print('Hello, world!')")?;
         std::fs::write(&one, "print('Hello, world!')")?;
 
-        let parent2 = site_packages.path().join("parent");
+        let parent2 = site_packages.join("parent");
         let child2 = parent2.join("child");
         let two = child2.join("two.py");
 
         std::fs::create_dir_all(&child2)?;
         std::fs::write(two, "print('Hello, world!')")?;
 
-        let one_module = db
-            .resolve_module(ModuleName::new("parent.child.one"))?
-            .unwrap();
+        let one_module = resolve_module(&db, ModuleName::new("parent.child.one"))?.unwrap();
 
-        assert_eq!(Some(one_module), db.path_to_module(&one)?);
+        assert_eq!(Some(one_module), path_to_module(&db, &one)?);
 
         assert_eq!(
             None,
-            db.resolve_module(ModuleName::new("parent.child.two"))?
+            resolve_module(&db, ModuleName::new("parent.child.two"))?
         );
         Ok(())
     }
@@ -961,21 +1161,22 @@ mod tests {
             src,
             site_packages,
             temp_dir: _temp_dir,
+            ..
         } = create_resolver()?;
 
-        let foo_src = src.path().join("foo.py");
-        let foo_site_packages = site_packages.path().join("foo.py");
+        let foo_src = src.join("foo.py");
+        let foo_site_packages = site_packages.join("foo.py");
 
         std::fs::write(&foo_src, "")?;
         std::fs::write(&foo_site_packages, "")?;
 
-        let foo_module = db.resolve_module(ModuleName::new("foo"))?.unwrap();
+        let foo_module = resolve_module(&db, ModuleName::new("foo"))?.unwrap();
 
-        assert_eq!(&src, foo_module.path(&db)?.root());
+        assert_eq!(&src, foo_module.path(&db)?.root().path());
         assert_eq!(&foo_src, &*db.file_path(foo_module.path(&db)?.file()));
 
-        assert_eq!(Some(foo_module), db.path_to_module(&foo_src)?);
-        assert_eq!(None, db.path_to_module(&foo_site_packages)?);
+        assert_eq!(Some(foo_module), path_to_module(&db, &foo_src)?);
+        assert_eq!(None, path_to_module(&db, &foo_site_packages)?);
 
         Ok(())
     }
@@ -990,28 +1191,28 @@ mod tests {
             ..
         } = create_resolver()?;
 
-        let foo = src.path().join("foo.py");
-        let bar = src.path().join("bar.py");
+        let foo = src.join("foo.py");
+        let bar = src.join("bar.py");
 
         std::fs::write(&foo, "")?;
         std::os::unix::fs::symlink(&foo, &bar)?;
 
-        let foo_module = db.resolve_module(ModuleName::new("foo"))?.unwrap();
-        let bar_module = db.resolve_module(ModuleName::new("bar"))?.unwrap();
+        let foo_module = resolve_module(&db, ModuleName::new("foo"))?.unwrap();
+        let bar_module = resolve_module(&db, ModuleName::new("bar"))?.unwrap();
 
         assert_ne!(foo_module, bar_module);
 
-        assert_eq!(&src, foo_module.path(&db)?.root());
+        assert_eq!(&src, foo_module.path(&db)?.root().path());
         assert_eq!(&foo, &*db.file_path(foo_module.path(&db)?.file()));
 
         // Bar has a different name but it should point to the same file.
 
-        assert_eq!(&src, bar_module.path(&db)?.root());
+        assert_eq!(&src, bar_module.path(&db)?.root().path());
         assert_eq!(foo_module.path(&db)?.file(), bar_module.path(&db)?.file());
         assert_eq!(&foo, &*db.file_path(bar_module.path(&db)?.file()));
 
-        assert_eq!(Some(foo_module), db.path_to_module(&foo)?);
-        assert_eq!(Some(bar_module), db.path_to_module(&bar)?);
+        assert_eq!(Some(foo_module), path_to_module(&db, &foo)?);
+        assert_eq!(Some(bar_module), path_to_module(&db, &bar)?);
 
         Ok(())
     }
@@ -1025,7 +1226,7 @@ mod tests {
             ..
         } = create_resolver()?;
 
-        let foo_dir = src.path().join("foo");
+        let foo_dir = src.join("foo");
         let foo_path = foo_dir.join("__init__.py");
         let bar_path = foo_dir.join("bar.py");
 
@@ -1033,8 +1234,8 @@ mod tests {
         std::fs::write(foo_path, "from .bar import test")?;
         std::fs::write(bar_path, "test = 'Hello world'")?;
 
-        let foo_module = db.resolve_module(ModuleName::new("foo"))?.unwrap();
-        let bar_module = db.resolve_module(ModuleName::new("foo.bar"))?.unwrap();
+        let foo_module = resolve_module(&db, ModuleName::new("foo"))?.unwrap();
+        let bar_module = resolve_module(&db, ModuleName::new("foo.bar"))?.unwrap();
 
         // `from . import bar` in `foo/__init__.py` resolves to `foo`
         assert_eq!(

crates/red_knot/src/parse.rs

@@ -1,87 +1,33 @@
 use std::ops::{Deref, DerefMut};
 use std::sync::Arc;
 
-use ruff_python_ast as ast;
-use ruff_python_parser::{Mode, ParseError};
-use ruff_text_size::{Ranged, TextRange};
+use ruff_python_ast::ModModule;
+use ruff_python_parser::Parsed;
 
 use crate::cache::KeyValueCache;
-use crate::db::{HasJar, QueryResult, SourceDb, SourceJar};
+use crate::db::{QueryResult, SourceDb};
 use crate::files::FileId;
-
-#[derive(Debug, Clone, PartialEq)]
-pub struct Parsed {
-    inner: Arc<ParsedInner>,
-}
-
-#[derive(Debug, PartialEq)]
-struct ParsedInner {
-    ast: ast::ModModule,
-    errors: Vec<ParseError>,
-}
-
-impl Parsed {
-    fn new(ast: ast::ModModule, errors: Vec<ParseError>) -> Self {
-        Self {
-            inner: Arc::new(ParsedInner { ast, errors }),
-        }
-    }
-
-    pub(crate) fn from_text(text: &str) -> Self {
-        let result = ruff_python_parser::parse(text, Mode::Module);
-
-        let (module, errors) = match result {
-            Ok(ast::Mod::Module(module)) => (module, vec![]),
-            Ok(ast::Mod::Expression(expression)) => (
-                ast::ModModule {
-                    range: expression.range(),
-                    body: vec![ast::Stmt::Expr(ast::StmtExpr {
-                        range: expression.range(),
-                        value: expression.body,
-                    })],
-                },
-                vec![],
-            ),
-            Err(errors) => (
-                ast::ModModule {
-                    range: TextRange::default(),
-                    body: Vec::new(),
-                },
-                vec![errors],
-            ),
-        };
-
-        Parsed::new(module, errors)
-    }
-
-    pub fn ast(&self) -> &ast::ModModule {
-        &self.inner.ast
-    }
-
-    pub fn errors(&self) -> &[ParseError] {
-        &self.inner.errors
-    }
-}
+use crate::source::source_text;
 
 #[tracing::instrument(level = "debug", skip(db))]
-pub(crate) fn parse<Db>(db: &Db, file_id: FileId) -> QueryResult<Parsed>
-where
-    Db: SourceDb + HasJar<SourceJar>,
-{
-    let parsed = db.jar()?;
+pub(crate) fn parse(db: &dyn SourceDb, file_id: FileId) -> QueryResult<Arc<Parsed<ModModule>>> {
+    let jar = db.jar()?;
 
-    parsed.parsed.get(&file_id, |file_id| {
-        let source = db.source(*file_id)?;
+    jar.parsed.get(&file_id, |file_id| {
+        let source = source_text(db, *file_id)?;
 
-        Ok(Parsed::from_text(source.text()))
+        Ok(Arc::new(ruff_python_parser::parse_unchecked_source(
+            source.text(),
+            source.kind().into(),
+        )))
     })
 }
 
 #[derive(Debug, Default)]
-pub struct ParsedStorage(KeyValueCache<FileId, Parsed>);
+pub struct ParsedStorage(KeyValueCache<FileId, Arc<Parsed<ModModule>>>);
 
 impl Deref for ParsedStorage {
-    type Target = KeyValueCache<FileId, Parsed>;
+    type Target = KeyValueCache<FileId, Arc<Parsed<ModModule>>>;
 
     fn deref(&self) -> &Self::Target {
         &self.0

crates/red_knot/src/program/check.rs

@@ -1,11 +1,12 @@
 use rayon::{current_num_threads, yield_local};
 use rustc_hash::FxHashSet;
 
-use crate::db::{Database, LintDb, QueryError, QueryResult, SemanticDb};
+use crate::db::{Database, QueryError, QueryResult};
 use crate::files::FileId;
-use crate::lint::Diagnostics;
+use crate::lint::{lint_semantic, lint_syntax, Diagnostics};
+use crate::module::{file_to_module, resolve_module};
 use crate::program::Program;
-use crate::symbols::Dependency;
+use crate::semantic::{semantic_index, Dependency};
 
 impl Program {
     /// Checks all open files in the workspace and its dependencies.
@@ -27,11 +28,11 @@ impl Program {
     fn check_file(&self, file: FileId, context: &CheckFileContext) -> QueryResult<Diagnostics> {
         self.cancelled()?;
 
-        let symbol_table = self.symbol_table(file)?;
-        let dependencies = symbol_table.dependencies();
+        let index = semantic_index(self, file)?;
+        let dependencies = index.symbol_table().dependencies();
 
         if !dependencies.is_empty() {
-            let module = self.file_to_module(file)?;
+            let module = file_to_module(self, file)?;
 
             // TODO scheduling all dependencies here is wasteful if we don't infer any types on them
             //  but I think that's unlikely, so it is okay?
@@ -50,7 +51,7 @@ impl Program {
                     // TODO We may want to have a different check functions for non-first-party
                     //   files because we only need to index them and not check them.
                     //   Supporting non-first-party code also requires supporting typing stubs.
-                    if let Some(dependency) = self.resolve_module(dependency_name)? {
+                    if let Some(dependency) = resolve_module(self, dependency_name)? {
                         if dependency.path(self)?.root().kind().is_first_party() {
                             context.schedule_dependency(dependency.path(self)?.file());
                         }
@@ -62,8 +63,8 @@ impl Program {
         let mut diagnostics = Vec::new();
 
         if self.workspace().is_file_open(file) {
-            diagnostics.extend_from_slice(&self.lint_syntax(file)?);
-            diagnostics.extend_from_slice(&self.lint_semantic(file)?);
+            diagnostics.extend_from_slice(&lint_syntax(self, file)?);
+            diagnostics.extend_from_slice(&lint_semantic(self, file)?);
         }
 
         Ok(Diagnostics::from(diagnostics))

crates/red_knot/src/program/mod.rs

@@ -5,19 +5,10 @@ use std::sync::Arc;
 use rustc_hash::FxHashMap;
 
 use crate::db::{
-    Database, Db, DbRuntime, HasJar, HasJars, JarsStorage, LintDb, LintJar, ParallelDatabase,
-    QueryResult, SemanticDb, SemanticJar, Snapshot, SourceDb, SourceJar,
+    Database, Db, DbRuntime, DbWithJar, HasJar, HasJars, JarsStorage, LintDb, LintJar,
+    ParallelDatabase, QueryResult, SemanticDb, SemanticJar, Snapshot, SourceDb, SourceJar, Upcast,
 };
 use crate::files::{FileId, Files};
-use crate::lint::{lint_semantic, lint_syntax, Diagnostics};
-use crate::module::{
-    add_module, file_to_module, path_to_module, resolve_module, set_module_search_paths, Module,
-    ModuleData, ModuleName, ModuleSearchPath,
-};
-use crate::parse::{parse, Parsed};
-use crate::source::{source_text, Source};
-use crate::symbols::{symbol_table, SymbolId, SymbolTable};
-use crate::types::{infer_symbol_type, Type};
 use crate::Workspace;
 
 pub mod check;
@@ -51,8 +42,8 @@ impl Program {
 
         let (source, semantic, lint) = self.jars_mut();
         for change in aggregated_changes.iter() {
-            semantic.module_resolver.remove_module(change.id);
-            semantic.symbol_tables.remove(&change.id);
+            semantic.module_resolver.remove_module_by_file(change.id);
+            semantic.semantic_indices.remove(&change.id);
             source.sources.remove(&change.id);
             source.parsed.remove(&change.id);
             // TODO: remove all dependent modules as well
@@ -83,54 +74,33 @@ impl SourceDb for Program {
     fn file_path(&self, file_id: FileId) -> Arc<Path> {
         self.files.path(file_id)
     }
+}
 
-    fn source(&self, file_id: FileId) -> QueryResult<Source> {
-        source_text(self, file_id)
-    }
+impl DbWithJar<SourceJar> for Program {}
 
-    fn parse(&self, file_id: FileId) -> QueryResult<Parsed> {
-        parse(self, file_id)
+impl SemanticDb for Program {}
+
+impl DbWithJar<SemanticJar> for Program {}
+
+impl LintDb for Program {}
+
+impl DbWithJar<LintJar> for Program {}
+
+impl Upcast<dyn SemanticDb> for Program {
+    fn upcast(&self) -> &(dyn SemanticDb + 'static) {
+        self
     }
 }
 
-impl SemanticDb for Program {
-    fn resolve_module(&self, name: ModuleName) -> QueryResult<Option<Module>> {
-        resolve_module(self, name)
-    }
-
-    fn file_to_module(&self, file_id: FileId) -> QueryResult<Option<Module>> {
-        file_to_module(self, file_id)
-    }
-
-    fn path_to_module(&self, path: &Path) -> QueryResult<Option<Module>> {
-        path_to_module(self, path)
-    }
-
-    fn symbol_table(&self, file_id: FileId) -> QueryResult<Arc<SymbolTable>> {
-        symbol_table(self, file_id)
-    }
-
-    fn infer_symbol_type(&self, file_id: FileId, symbol_id: SymbolId) -> QueryResult<Type> {
-        infer_symbol_type(self, file_id, symbol_id)
-    }
-
-    // Mutations
-    fn add_module(&mut self, path: &Path) -> Option<(Module, Vec<Arc<ModuleData>>)> {
-        add_module(self, path)
-    }
-
-    fn set_module_search_paths(&mut self, paths: Vec<ModuleSearchPath>) {
-        set_module_search_paths(self, paths);
+impl Upcast<dyn SourceDb> for Program {
+    fn upcast(&self) -> &(dyn SourceDb + 'static) {
+        self
     }
 }
 
-impl LintDb for Program {
-    fn lint_syntax(&self, file_id: FileId) -> QueryResult<Diagnostics> {
-        lint_syntax(self, file_id)
-    }
-
-    fn lint_semantic(&self, file_id: FileId) -> QueryResult<Diagnostics> {
-        lint_semantic(self, file_id)
+impl Upcast<dyn LintDb> for Program {
+    fn upcast(&self) -> &(dyn LintDb + 'static) {
+        self
     }
 }
 

crates/red_knot/src/semantic.rs

@@ -0,0 +1,883 @@
+use std::num::NonZeroU32;
+
+use ruff_python_ast as ast;
+use ruff_python_ast::visitor::source_order::SourceOrderVisitor;
+use ruff_python_ast::AstNode;
+
+use crate::ast_ids::{NodeKey, TypedNodeKey};
+use crate::cache::KeyValueCache;
+use crate::db::{QueryResult, SemanticDb, SemanticJar};
+use crate::files::FileId;
+use crate::module::Module;
+use crate::module::ModuleName;
+use crate::parse::parse;
+use crate::Name;
+pub(crate) use definitions::Definition;
+use definitions::{ImportDefinition, ImportFromDefinition};
+pub(crate) use flow_graph::ConstrainedDefinition;
+use flow_graph::{FlowGraph, FlowGraphBuilder, FlowNodeId, ReachableDefinitionsIterator};
+use ruff_index::{newtype_index, IndexVec};
+use rustc_hash::FxHashMap;
+use std::ops::{Deref, DerefMut};
+use std::sync::Arc;
+pub(crate) use symbol_table::{Dependency, SymbolId};
+use symbol_table::{ScopeId, ScopeKind, SymbolFlags, SymbolTable, SymbolTableBuilder};
+pub(crate) use types::{infer_definition_type, infer_symbol_public_type, Type, TypeStore};
+
+mod definitions;
+mod flow_graph;
+mod symbol_table;
+mod types;
+
+#[tracing::instrument(level = "debug", skip(db))]
+pub fn semantic_index(db: &dyn SemanticDb, file_id: FileId) -> QueryResult<Arc<SemanticIndex>> {
+    let jar: &SemanticJar = db.jar()?;
+
+    jar.semantic_indices.get(&file_id, |_| {
+        let parsed = parse(db.upcast(), file_id)?;
+        Ok(Arc::from(SemanticIndex::from_ast(parsed.syntax())))
+    })
+}
+
+#[tracing::instrument(level = "debug", skip(db))]
+pub fn resolve_global_symbol(
+    db: &dyn SemanticDb,
+    module: Module,
+    name: &str,
+) -> QueryResult<Option<GlobalSymbolId>> {
+    let file_id = module.path(db)?.file();
+    let symbol_table = &semantic_index(db, file_id)?.symbol_table;
+    let Some(symbol_id) = symbol_table.root_symbol_id_by_name(name) else {
+        return Ok(None);
+    };
+    Ok(Some(GlobalSymbolId { file_id, symbol_id }))
+}
+
+#[newtype_index]
+pub struct ExpressionId;
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub struct GlobalSymbolId {
+    pub(crate) file_id: FileId,
+    pub(crate) symbol_id: SymbolId,
+}
+
+#[derive(Debug)]
+pub struct SemanticIndex {
+    symbol_table: SymbolTable,
+    flow_graph: FlowGraph,
+    expressions: FxHashMap<NodeKey, ExpressionId>,
+    expressions_by_id: IndexVec<ExpressionId, NodeKey>,
+}
+
+impl SemanticIndex {
+    pub fn from_ast(module: &ast::ModModule) -> Self {
+        let root_scope_id = SymbolTable::root_scope_id();
+        let mut indexer = SemanticIndexer {
+            symbol_table_builder: SymbolTableBuilder::new(),
+            flow_graph_builder: FlowGraphBuilder::new(),
+            scopes: vec![ScopeState {
+                scope_id: root_scope_id,
+                current_flow_node_id: FlowGraph::start(),
+            }],
+            expressions: FxHashMap::default(),
+            expressions_by_id: IndexVec::default(),
+            current_definition: None,
+        };
+        indexer.visit_body(&module.body);
+        indexer.finish()
+    }
+
+    fn resolve_expression_id<'a>(
+        &self,
+        ast: &'a ast::ModModule,
+        expression_id: ExpressionId,
+    ) -> ast::AnyNodeRef<'a> {
+        let node_key = self.expressions_by_id[expression_id];
+        node_key
+            .resolve(ast.as_any_node_ref())
+            .expect("node to resolve")
+    }
+
+    /// Return an iterator over all definitions of `symbol_id` reachable from `use_expr`. The value
+    /// of `symbol_id` in `use_expr` must originate from one of the iterated definitions (or from
+    /// an external reassignment of the name outside of this scope).
+    pub fn reachable_definitions(
+        &self,
+        symbol_id: SymbolId,
+        use_expr: &ast::Expr,
+    ) -> ReachableDefinitionsIterator {
+        let expression_id = self.expression_id(use_expr);
+        ReachableDefinitionsIterator::new(
+            &self.flow_graph,
+            symbol_id,
+            self.flow_graph.for_expr(expression_id),
+        )
+    }
+
+    pub fn expression_id(&self, expression: &ast::Expr) -> ExpressionId {
+        self.expressions[&NodeKey::from_node(expression.into())]
+    }
+
+    pub fn symbol_table(&self) -> &SymbolTable {
+        &self.symbol_table
+    }
+}
+
+#[derive(Debug)]
+struct ScopeState {
+    scope_id: ScopeId,
+    current_flow_node_id: FlowNodeId,
+}
+
+#[derive(Debug)]
+struct SemanticIndexer {
+    symbol_table_builder: SymbolTableBuilder,
+    flow_graph_builder: FlowGraphBuilder,
+    scopes: Vec<ScopeState>,
+    /// the definition whose target(s) we are currently walking
+    current_definition: Option<Definition>,
+    expressions: FxHashMap<NodeKey, ExpressionId>,
+    expressions_by_id: IndexVec<ExpressionId, NodeKey>,
+}
+
+impl SemanticIndexer {
+    pub(crate) fn finish(mut self) -> SemanticIndex {
+        let SemanticIndexer {
+            flow_graph_builder,
+            symbol_table_builder,
+            ..
+        } = self;
+        self.expressions.shrink_to_fit();
+        self.expressions_by_id.shrink_to_fit();
+        SemanticIndex {
+            flow_graph: flow_graph_builder.finish(),
+            symbol_table: symbol_table_builder.finish(),
+            expressions: self.expressions,
+            expressions_by_id: self.expressions_by_id,
+        }
+    }
+
+    fn set_current_flow_node(&mut self, new_flow_node_id: FlowNodeId) {
+        let scope_state = self.scopes.last_mut().expect("scope stack is never empty");
+        scope_state.current_flow_node_id = new_flow_node_id;
+    }
+
+    fn current_flow_node(&self) -> FlowNodeId {
+        self.scopes
+            .last()
+            .expect("scope stack is never empty")
+            .current_flow_node_id
+    }
+
+    fn add_or_update_symbol(&mut self, identifier: &str, flags: SymbolFlags) -> SymbolId {
+        self.symbol_table_builder
+            .add_or_update_symbol(self.cur_scope(), identifier, flags)
+    }
+
+    fn add_or_update_symbol_with_def(
+        &mut self,
+        identifier: &str,
+        definition: Definition,
+    ) -> SymbolId {
+        let symbol_id = self.add_or_update_symbol(identifier, SymbolFlags::IS_DEFINED);
+        self.symbol_table_builder
+            .add_definition(symbol_id, definition.clone());
+        let new_flow_node_id =
+            self.flow_graph_builder
+                .add_definition(symbol_id, definition, self.current_flow_node());
+        self.set_current_flow_node(new_flow_node_id);
+        symbol_id
+    }
+
+    fn push_scope(
+        &mut self,
+        name: &str,
+        kind: ScopeKind,
+        definition: Option<Definition>,
+        defining_symbol: Option<SymbolId>,
+    ) -> ScopeId {
+        let scope_id = self.symbol_table_builder.add_child_scope(
+            self.cur_scope(),
+            name,
+            kind,
+            definition,
+            defining_symbol,
+        );
+        self.scopes.push(ScopeState {
+            scope_id,
+            current_flow_node_id: FlowGraph::start(),
+        });
+        scope_id
+    }
+
+    fn pop_scope(&mut self) -> ScopeId {
+        self.scopes
+            .pop()
+            .expect("Scope stack should never be empty")
+            .scope_id
+    }
+
+    fn cur_scope(&self) -> ScopeId {
+        self.scopes
+            .last()
+            .expect("Scope stack should never be empty")
+            .scope_id
+    }
+
+    fn record_scope_for_node(&mut self, node_key: NodeKey, scope_id: ScopeId) {
+        self.symbol_table_builder
+            .record_scope_for_node(node_key, scope_id);
+    }
+
+    fn insert_constraint(&mut self, expr: &ast::Expr) {
+        let node_key = NodeKey::from_node(expr.into());
+        let expression_id = self.expressions[&node_key];
+        let constraint = self
+            .flow_graph_builder
+            .add_constraint(self.current_flow_node(), expression_id);
+        self.set_current_flow_node(constraint);
+    }
+
+    fn with_type_params(
+        &mut self,
+        name: &str,
+        params: &Option<Box<ast::TypeParams>>,
+        definition: Option<Definition>,
+        defining_symbol: Option<SymbolId>,
+        nested: impl FnOnce(&mut Self) -> ScopeId,
+    ) -> ScopeId {
+        if let Some(type_params) = params {
+            self.push_scope(name, ScopeKind::Annotation, definition, defining_symbol);
+            for type_param in &type_params.type_params {
+                let name = match type_param {
+                    ast::TypeParam::TypeVar(ast::TypeParamTypeVar { name, .. }) => name,
+                    ast::TypeParam::ParamSpec(ast::TypeParamParamSpec { name, .. }) => name,
+                    ast::TypeParam::TypeVarTuple(ast::TypeParamTypeVarTuple { name, .. }) => name,
+                };
+                self.add_or_update_symbol(name, SymbolFlags::IS_DEFINED);
+            }
+        }
+        let scope_id = nested(self);
+        if params.is_some() {
+            self.pop_scope();
+        }
+        scope_id
+    }
+}
+
+impl SourceOrderVisitor<'_> for SemanticIndexer {
+    fn visit_expr(&mut self, expr: &ast::Expr) {
+        let node_key = NodeKey::from_node(expr.into());
+        let expression_id = self.expressions_by_id.push(node_key);
+
+        debug_assert_eq!(
+            expression_id,
+            self.flow_graph_builder
+                .record_expr(self.current_flow_node())
+        );
+
+        debug_assert_eq!(
+            expression_id,
+            self.symbol_table_builder
+                .record_expression(self.cur_scope())
+        );
+
+        self.expressions.insert(node_key, expression_id);
+
+        match expr {
+            ast::Expr::Name(ast::ExprName { id, ctx, .. }) => {
+                let flags = match ctx {
+                    ast::ExprContext::Load => SymbolFlags::IS_USED,
+                    ast::ExprContext::Store => SymbolFlags::IS_DEFINED,
+                    ast::ExprContext::Del => SymbolFlags::IS_DEFINED,
+                    ast::ExprContext::Invalid => SymbolFlags::empty(),
+                };
+                self.add_or_update_symbol(id, flags);
+                if flags.contains(SymbolFlags::IS_DEFINED) {
+                    if let Some(curdef) = self.current_definition.clone() {
+                        self.add_or_update_symbol_with_def(id, curdef);
+                    }
+                }
+                ast::visitor::source_order::walk_expr(self, expr);
+            }
+            ast::Expr::Named(node) => {
+                debug_assert!(self.current_definition.is_none());
+                self.current_definition =
+                    Some(Definition::NamedExpr(TypedNodeKey::from_node(node)));
+                // TODO walrus in comprehensions is implicitly nonlocal
+                self.visit_expr(&node.target);
+                self.current_definition = None;
+                self.visit_expr(&node.value);
+            }
+            ast::Expr::If(ast::ExprIf {
+                body, test, orelse, ..
+            }) => {
+                // TODO detect statically known truthy or falsy test (via type inference, not naive
+                // AST inspection, so we can't simplify here, need to record test expression in CFG
+                // for later checking)
+
+                self.visit_expr(test);
+
+                let if_branch = self.flow_graph_builder.add_branch(self.current_flow_node());
+
+                self.set_current_flow_node(if_branch);
+                self.insert_constraint(test);
+                self.visit_expr(body);
+
+                let post_body = self.current_flow_node();
+
+                self.set_current_flow_node(if_branch);
+                self.visit_expr(orelse);
+
+                let post_else = self
+                    .flow_graph_builder
+                    .add_phi(self.current_flow_node(), post_body);
+
+                self.set_current_flow_node(post_else);
+            }
+            _ => {
+                ast::visitor::source_order::walk_expr(self, expr);
+            }
+        }
+    }
+
+    fn visit_stmt(&mut self, stmt: &ast::Stmt) {
+        // TODO need to capture more definition statements here
+        match stmt {
+            ast::Stmt::ClassDef(node) => {
+                let node_key = TypedNodeKey::from_node(node);
+                let def = Definition::ClassDef(node_key.clone());
+                let symbol_id = self.add_or_update_symbol_with_def(&node.name, def.clone());
+                for decorator in &node.decorator_list {
+                    self.visit_decorator(decorator);
+                }
+                let scope_id = self.with_type_params(
+                    &node.name,
+                    &node.type_params,
+                    Some(def.clone()),
+                    Some(symbol_id),
+                    |indexer| {
+                        if let Some(arguments) = &node.arguments {
+                            indexer.visit_arguments(arguments);
+                        }
+                        let scope_id = indexer.push_scope(
+                            &node.name,
+                            ScopeKind::Class,
+                            Some(def.clone()),
+                            Some(symbol_id),
+                        );
+                        indexer.visit_body(&node.body);
+                        indexer.pop_scope();
+                        scope_id
+                    },
+                );
+                self.record_scope_for_node(*node_key.erased(), scope_id);
+            }
+            ast::Stmt::FunctionDef(node) => {
+                let node_key = TypedNodeKey::from_node(node);
+                let def = Definition::FunctionDef(node_key.clone());
+                let symbol_id = self.add_or_update_symbol_with_def(&node.name, def.clone());
+                for decorator in &node.decorator_list {
+                    self.visit_decorator(decorator);
+                }
+                let scope_id = self.with_type_params(
+                    &node.name,
+                    &node.type_params,
+                    Some(def.clone()),
+                    Some(symbol_id),
+                    |indexer| {
+                        indexer.visit_parameters(&node.parameters);
+                        for expr in &node.returns {
+                            indexer.visit_annotation(expr);
+                        }
+                        let scope_id = indexer.push_scope(
+                            &node.name,
+                            ScopeKind::Function,
+                            Some(def.clone()),
+                            Some(symbol_id),
+                        );
+                        indexer.visit_body(&node.body);
+                        indexer.pop_scope();
+                        scope_id
+                    },
+                );
+                self.record_scope_for_node(*node_key.erased(), scope_id);
+            }
+            ast::Stmt::Import(ast::StmtImport { names, .. }) => {
+                for alias in names {
+                    let symbol_name = if let Some(asname) = &alias.asname {
+                        asname.id.as_str()
+                    } else {
+                        alias.name.id.split('.').next().unwrap()
+                    };
+
+                    let module = ModuleName::new(&alias.name.id);
+
+                    let def = Definition::Import(ImportDefinition {
+                        module: module.clone(),
+                    });
+                    self.add_or_update_symbol_with_def(symbol_name, def);
+                    self.symbol_table_builder
+                        .add_dependency(Dependency::Module(module));
+                }
+            }
+            ast::Stmt::ImportFrom(ast::StmtImportFrom {
+                module,
+                names,
+                level,
+                ..
+            }) => {
+                let module = module.as_ref().map(|m| ModuleName::new(&m.id));
+
+                for alias in names {
+                    let symbol_name = if let Some(asname) = &alias.asname {
+                        asname.id.as_str()
+                    } else {
+                        alias.name.id.as_str()
+                    };
+                    let def = Definition::ImportFrom(ImportFromDefinition {
+                        module: module.clone(),
+                        name: Name::new(&alias.name.id),
+                        level: *level,
+                    });
+                    self.add_or_update_symbol_with_def(symbol_name, def);
+                }
+
+                let dependency = if let Some(module) = module {
+                    match NonZeroU32::new(*level) {
+                        Some(level) => Dependency::Relative {
+                            level,
+                            module: Some(module),
+                        },
+                        None => Dependency::Module(module),
+                    }
+                } else {
+                    Dependency::Relative {
+                        level: NonZeroU32::new(*level)
+                            .expect("Import without a module to have a level > 0"),
+                        module,
+                    }
+                };
+
+                self.symbol_table_builder.add_dependency(dependency);
+            }
+            ast::Stmt::Assign(node) => {
+                debug_assert!(self.current_definition.is_none());
+                self.visit_expr(&node.value);
+                self.current_definition =
+                    Some(Definition::Assignment(TypedNodeKey::from_node(node)));
+                for expr in &node.targets {
+                    self.visit_expr(expr);
+                }
+
+                self.current_definition = None;
+            }
+            ast::Stmt::If(node) => {
+                // TODO detect statically known truthy or falsy test (via type inference, not naive
+                // AST inspection, so we can't simplify here, need to record test expression in CFG
+                // for later checking)
+
+                // we visit the if "test" condition first regardless
+                self.visit_expr(&node.test);
+
+                // create branch node: does the if test pass or not?
+                let if_branch = self.flow_graph_builder.add_branch(self.current_flow_node());
+
+                // visit the body of the `if` clause
+                self.set_current_flow_node(if_branch);
+                self.insert_constraint(&node.test);
+                self.visit_body(&node.body);
+
+                // Flow node for the last if/elif condition branch; represents the "no branch
+                // taken yet" possibility (where "taking a branch" means that the condition in an
+                // if or elif evaluated to true and control flow went into that clause).
+                let mut prior_branch = if_branch;
+
+                // Flow node for the state after the prior if/elif/else clause; represents "we have
+                // taken one of the branches up to this point." Initially set to the post-if-clause
+                // state, later will be set to the phi node joining that possible path with the
+                // possibility that we took a later if/elif/else clause instead.
+                let mut post_prior_clause = self.current_flow_node();
+
+                // Flag to mark if the final clause is an "else" -- if so, that means the "match no
+                // clauses" path is not possible, we have to go through one of the clauses.
+                let mut last_branch_is_else = false;
+
+                for clause in &node.elif_else_clauses {
+                    if let Some(test) = &clause.test {
+                        self.visit_expr(test);
+                        // This is an elif clause. Create a new branch node. Its predecessor is the
+                        // previous branch node, because we can only take one branch in an entire
+                        // if/elif/else chain, so if we take this branch, it can only be because we
+                        // didn't take the previous one.
+                        prior_branch = self.flow_graph_builder.add_branch(prior_branch);
+                        self.set_current_flow_node(prior_branch);
+                        self.insert_constraint(test);
+                    } else {
+                        // This is an else clause. No need to create a branch node; there's no
+                        // branch here, if we haven't taken any previous branch, we definitely go
+                        // into the "else" clause.
+                        self.set_current_flow_node(prior_branch);
+                        last_branch_is_else = true;
+                    }
+                    self.visit_elif_else_clause(clause);
+                    // Update `post_prior_clause` to a new phi node joining the possibility that we
+                    // took any of the previous branches with the possibility that we took the one
+                    // just visited.
+                    post_prior_clause = self
+                        .flow_graph_builder
+                        .add_phi(self.current_flow_node(), post_prior_clause);
+                }
+
+                if !last_branch_is_else {
+                    // Final branch was not an "else", which means it's possible we took zero
+                    // branches in the entire if/elif chain, so we need one more phi node to join
+                    // the "no branches taken" possibility.
+                    post_prior_clause = self
+                        .flow_graph_builder
+                        .add_phi(post_prior_clause, prior_branch);
+                }
+
+                // Onward, with current flow node set to our final Phi node.
+                self.set_current_flow_node(post_prior_clause);
+            }
+            _ => {
+                ast::visitor::source_order::walk_stmt(self, stmt);
+            }
+        }
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct SemanticIndexStorage(KeyValueCache<FileId, Arc<SemanticIndex>>);
+
+impl Deref for SemanticIndexStorage {
+    type Target = KeyValueCache<FileId, Arc<SemanticIndex>>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for SemanticIndexStorage {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::semantic::symbol_table::{Symbol, SymbolIterator};
+    use ruff_python_ast as ast;
+    use ruff_python_ast::ModModule;
+    use ruff_python_parser::{Mode, Parsed};
+
+    use super::{Definition, ScopeKind, SemanticIndex, SymbolId};
+
+    fn parse(code: &str) -> Parsed<ModModule> {
+        ruff_python_parser::parse_unchecked(code, Mode::Module)
+            .try_into_module()
+            .unwrap()
+    }
+
+    fn names<I>(it: SymbolIterator<I>) -> Vec<&str>
+    where
+        I: Iterator<Item = SymbolId>,
+    {
+        let mut symbols: Vec<_> = it.map(Symbol::name).collect();
+        symbols.sort_unstable();
+        symbols
+    }
+
+    #[test]
+    fn empty() {
+        let parsed = parse("");
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()).len(), 0);
+    }
+
+    #[test]
+    fn simple() {
+        let parsed = parse("x");
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["x"]);
+        assert_eq!(
+            table
+                .definitions(table.root_symbol_id_by_name("x").unwrap())
+                .len(),
+            0
+        );
+    }
+
+    #[test]
+    fn annotation_only() {
+        let parsed = parse("x: int");
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["int", "x"]);
+        // TODO record definition
+    }
+
+    #[test]
+    fn import() {
+        let parsed = parse("import foo");
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["foo"]);
+        assert_eq!(
+            table
+                .definitions(table.root_symbol_id_by_name("foo").unwrap())
+                .len(),
+            1
+        );
+    }
+
+    #[test]
+    fn import_sub() {
+        let parsed = parse("import foo.bar");
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["foo"]);
+    }
+
+    #[test]
+    fn import_as() {
+        let parsed = parse("import foo.bar as baz");
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["baz"]);
+    }
+
+    #[test]
+    fn import_from() {
+        let parsed = parse("from bar import foo");
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["foo"]);
+        assert_eq!(
+            table
+                .definitions(table.root_symbol_id_by_name("foo").unwrap())
+                .len(),
+            1
+        );
+        assert!(
+            table.root_symbol_id_by_name("foo").is_some_and(|sid| {
+                let s = sid.symbol(&table);
+                s.is_defined() || !s.is_used()
+            }),
+            "symbols that are defined get the defined flag"
+        );
+    }
+
+    #[test]
+    fn assign() {
+        let parsed = parse("x = foo");
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["foo", "x"]);
+        assert_eq!(
+            table
+                .definitions(table.root_symbol_id_by_name("x").unwrap())
+                .len(),
+            1
+        );
+        assert!(
+            table.root_symbol_id_by_name("foo").is_some_and(|sid| {
+                let s = sid.symbol(&table);
+                !s.is_defined() && s.is_used()
+            }),
+            "a symbol used but not defined in a scope should have only the used flag"
+        );
+    }
+
+    #[test]
+    fn class_scope() {
+        let parsed = parse(
+            "
+                class C:
+                    x = 1
+                y = 2
+                ",
+        );
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["C", "y"]);
+        let scopes = table.root_child_scope_ids();
+        assert_eq!(scopes.len(), 1);
+        let c_scope = scopes[0].scope(&table);
+        assert_eq!(c_scope.kind(), ScopeKind::Class);
+        assert_eq!(c_scope.name(), "C");
+        assert_eq!(names(table.symbols_for_scope(scopes[0])), vec!["x"]);
+        assert_eq!(
+            table
+                .definitions(table.root_symbol_id_by_name("C").unwrap())
+                .len(),
+            1
+        );
+    }
+
+    #[test]
+    fn func_scope() {
+        let parsed = parse(
+            "
+                def func():
+                    x = 1
+                y = 2
+                ",
+        );
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["func", "y"]);
+        let scopes = table.root_child_scope_ids();
+        assert_eq!(scopes.len(), 1);
+        let func_scope = scopes[0].scope(&table);
+        assert_eq!(func_scope.kind(), ScopeKind::Function);
+        assert_eq!(func_scope.name(), "func");
+        assert_eq!(names(table.symbols_for_scope(scopes[0])), vec!["x"]);
+        assert_eq!(
+            table
+                .definitions(table.root_symbol_id_by_name("func").unwrap())
+                .len(),
+            1
+        );
+    }
+
+    #[test]
+    fn dupes() {
+        let parsed = parse(
+            "
+                def func():
+                    x = 1
+                def func():
+                    y = 2
+                ",
+        );
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["func"]);
+        let scopes = table.root_child_scope_ids();
+        assert_eq!(scopes.len(), 2);
+        let func_scope_1 = scopes[0].scope(&table);
+        let func_scope_2 = scopes[1].scope(&table);
+        assert_eq!(func_scope_1.kind(), ScopeKind::Function);
+        assert_eq!(func_scope_1.name(), "func");
+        assert_eq!(func_scope_2.kind(), ScopeKind::Function);
+        assert_eq!(func_scope_2.name(), "func");
+        assert_eq!(names(table.symbols_for_scope(scopes[0])), vec!["x"]);
+        assert_eq!(names(table.symbols_for_scope(scopes[1])), vec!["y"]);
+        assert_eq!(
+            table
+                .definitions(table.root_symbol_id_by_name("func").unwrap())
+                .len(),
+            2
+        );
+    }
+
+    #[test]
+    fn generic_func() {
+        let parsed = parse(
+            "
+                def func[T]():
+                    x = 1
+                ",
+        );
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["func"]);
+        let scopes = table.root_child_scope_ids();
+        assert_eq!(scopes.len(), 1);
+        let ann_scope_id = scopes[0];
+        let ann_scope = ann_scope_id.scope(&table);
+        assert_eq!(ann_scope.kind(), ScopeKind::Annotation);
+        assert_eq!(ann_scope.name(), "func");
+        assert_eq!(names(table.symbols_for_scope(ann_scope_id)), vec!["T"]);
+        let scopes = table.child_scope_ids_of(ann_scope_id);
+        assert_eq!(scopes.len(), 1);
+        let func_scope_id = scopes[0];
+        let func_scope = func_scope_id.scope(&table);
+        assert_eq!(func_scope.kind(), ScopeKind::Function);
+        assert_eq!(func_scope.name(), "func");
+        assert_eq!(names(table.symbols_for_scope(func_scope_id)), vec!["x"]);
+    }
+
+    #[test]
+    fn generic_class() {
+        let parsed = parse(
+            "
+                class C[T]:
+                    x = 1
+                ",
+        );
+        let table = SemanticIndex::from_ast(parsed.syntax()).symbol_table;
+        assert_eq!(names(table.root_symbols()), vec!["C"]);
+        let scopes = table.root_child_scope_ids();
+        assert_eq!(scopes.len(), 1);
+        let ann_scope_id = scopes[0];
+        let ann_scope = ann_scope_id.scope(&table);
+        assert_eq!(ann_scope.kind(), ScopeKind::Annotation);
+        assert_eq!(ann_scope.name(), "C");
+        assert_eq!(names(table.symbols_for_scope(ann_scope_id)), vec!["T"]);
+        assert!(
+            table
+                .symbol_by_name(ann_scope_id, "T")
+                .is_some_and(|s| s.is_defined() && !s.is_used()),
+            "type parameters are defined by the scope that introduces them"
+        );
+        let scopes = table.child_scope_ids_of(ann_scope_id);
+        assert_eq!(scopes.len(), 1);
+        let func_scope_id = scopes[0];
+        let func_scope = func_scope_id.scope(&table);
+        assert_eq!(func_scope.kind(), ScopeKind::Class);
+        assert_eq!(func_scope.name(), "C");
+        assert_eq!(names(table.symbols_for_scope(func_scope_id)), vec!["x"]);
+    }
+
+    #[test]
+    fn reachability_trivial() {
+        let parsed = parse("x = 1; x");
+        let ast = parsed.syntax();
+        let index = SemanticIndex::from_ast(ast);
+        let table = &index.symbol_table;
+        let x_sym = table
+            .root_symbol_id_by_name("x")
+            .expect("x symbol should exist");
+        let ast::Stmt::Expr(ast::StmtExpr { value: x_use, .. }) = &ast.body[1] else {
+            panic!("should be an expr")
+        };
+        let x_defs: Vec<_> = index
+            .reachable_definitions(x_sym, x_use)
+            .map(|constrained_definition| constrained_definition.definition)
+            .collect();
+        assert_eq!(x_defs.len(), 1);
+        let Definition::Assignment(node_key) = &x_defs[0] else {
+            panic!("def should be an assignment")
+        };
+        let Some(def_node) = node_key.resolve(ast.into()) else {
+            panic!("node key should resolve")
+        };
+        let ast::Expr::NumberLiteral(ast::ExprNumberLiteral {
+            value: ast::Number::Int(num),
+            ..
+        }) = &*def_node.value
+        else {
+            panic!("should be a number literal")
+        };
+        assert_eq!(*num, 1);
+    }
+
+    #[test]
+    fn expression_scope() {
+        let parsed = parse("x = 1;\ndef test():\n  y = 4");
+        let ast = parsed.syntax();
+        let index = SemanticIndex::from_ast(ast);
+        let table = &index.symbol_table;
+
+        let x_sym = table
+            .root_symbol_by_name("x")
+            .expect("x symbol should exist");
+
+        let x_stmt = ast.body[0].as_assign_stmt().unwrap();
+
+        let x_id = index.expression_id(&x_stmt.targets[0]);
+
+        assert_eq!(table.scope_of_expression(x_id).kind(), ScopeKind::Module);
+        assert_eq!(table.scope_id_of_expression(x_id), x_sym.scope_id());
+
+        let def = ast.body[1].as_function_def_stmt().unwrap();
+        let y_stmt = def.body[0].as_assign_stmt().unwrap();
+        let y_id = index.expression_id(&y_stmt.targets[0]);
+
+        assert_eq!(table.scope_of_expression(y_id).kind(), ScopeKind::Function);
+    }
+}

crates/red_knot/src/semantic/definitions.rs

@@ -0,0 +1,52 @@
+use crate::ast_ids::TypedNodeKey;
+use crate::semantic::ModuleName;
+use crate::Name;
+use ruff_python_ast as ast;
+
+// TODO storing TypedNodeKey for definitions means we have to search to find them again in the AST;
+// this is at best O(log n). If looking up definitions is a bottleneck we should look for
+// alternatives here.
+// TODO intern Definitions in SymbolTable and reference using IDs?
+#[derive(Clone, Debug)]
+pub enum Definition {
+    // For the import cases, we don't need reference to any arbitrary AST subtrees (annotations,
+    // RHS), and referencing just the import statement node is imprecise (a single import statement
+    // can assign many symbols, we'd have to re-search for the one we care about), so we just copy
+    // the small amount of information we need from the AST.
+    Import(ImportDefinition),
+    ImportFrom(ImportFromDefinition),
+    ClassDef(TypedNodeKey<ast::StmtClassDef>),
+    FunctionDef(TypedNodeKey<ast::StmtFunctionDef>),
+    Assignment(TypedNodeKey<ast::StmtAssign>),
+    AnnotatedAssignment(TypedNodeKey<ast::StmtAnnAssign>),
+    NamedExpr(TypedNodeKey<ast::ExprNamed>),
+    /// represents the implicit initial definition of every name as "unbound"
+    Unbound,
+    // TODO with statements, except handlers, function args...
+}
+
+#[derive(Clone, Debug)]
+pub struct ImportDefinition {
+    pub module: ModuleName,
+}
+
+#[derive(Clone, Debug)]
+pub struct ImportFromDefinition {
+    pub module: Option<ModuleName>,
+    pub name: Name,
+    pub level: u32,
+}
+
+impl ImportFromDefinition {
+    pub fn module(&self) -> Option<&ModuleName> {
+        self.module.as_ref()
+    }
+
+    pub fn name(&self) -> &Name {
+        &self.name
+    }
+
+    pub fn level(&self) -> u32 {
+        self.level
+    }
+}

crates/red_knot/src/semantic/flow_graph.rs

@@ -0,0 +1,270 @@
+use super::symbol_table::SymbolId;
+use crate::semantic::{Definition, ExpressionId};
+use ruff_index::{newtype_index, IndexVec};
+use std::iter::FusedIterator;
+use std::ops::Range;
+
+#[newtype_index]
+pub struct FlowNodeId;
+
+#[derive(Debug)]
+pub(crate) enum FlowNode {
+    Start,
+    Definition(DefinitionFlowNode),
+    Branch(BranchFlowNode),
+    Phi(PhiFlowNode),
+    Constraint(ConstraintFlowNode),
+}
+
+/// A point in control flow where a symbol is defined
+#[derive(Debug)]
+pub(crate) struct DefinitionFlowNode {
+    symbol_id: SymbolId,
+    definition: Definition,
+    predecessor: FlowNodeId,
+}
+
+/// A branch in control flow
+#[derive(Debug)]
+pub(crate) struct BranchFlowNode {
+    predecessor: FlowNodeId,
+}
+
+/// A join point where control flow paths come together
+#[derive(Debug)]
+pub(crate) struct PhiFlowNode {
+    first_predecessor: FlowNodeId,
+    second_predecessor: FlowNodeId,
+}
+
+/// A branch test which may apply constraints to a symbol's type
+#[derive(Debug)]
+pub(crate) struct ConstraintFlowNode {
+    predecessor: FlowNodeId,
+    test_expression: ExpressionId,
+}
+
+#[derive(Debug)]
+pub struct FlowGraph {
+    flow_nodes_by_id: IndexVec<FlowNodeId, FlowNode>,
+    expression_map: IndexVec<ExpressionId, FlowNodeId>,
+}
+
+impl FlowGraph {
+    pub fn start() -> FlowNodeId {
+        FlowNodeId::from_usize(0)
+    }
+
+    pub fn for_expr(&self, expr: ExpressionId) -> FlowNodeId {
+        self.expression_map[expr]
+    }
+}
+
+#[derive(Debug)]
+pub(crate) struct FlowGraphBuilder {
+    flow_graph: FlowGraph,
+}
+
+impl FlowGraphBuilder {
+    pub(crate) fn new() -> Self {
+        let mut graph = FlowGraph {
+            flow_nodes_by_id: IndexVec::default(),
+            expression_map: IndexVec::default(),
+        };
+        graph.flow_nodes_by_id.push(FlowNode::Start);
+        Self { flow_graph: graph }
+    }
+
+    pub(crate) fn add(&mut self, node: FlowNode) -> FlowNodeId {
+        self.flow_graph.flow_nodes_by_id.push(node)
+    }
+
+    pub(crate) fn add_definition(
+        &mut self,
+        symbol_id: SymbolId,
+        definition: Definition,
+        predecessor: FlowNodeId,
+    ) -> FlowNodeId {
+        self.add(FlowNode::Definition(DefinitionFlowNode {
+            symbol_id,
+            definition,
+            predecessor,
+        }))
+    }
+
+    pub(crate) fn add_branch(&mut self, predecessor: FlowNodeId) -> FlowNodeId {
+        self.add(FlowNode::Branch(BranchFlowNode { predecessor }))
+    }
+
+    pub(crate) fn add_phi(
+        &mut self,
+        first_predecessor: FlowNodeId,
+        second_predecessor: FlowNodeId,
+    ) -> FlowNodeId {
+        self.add(FlowNode::Phi(PhiFlowNode {
+            first_predecessor,
+            second_predecessor,
+        }))
+    }
+
+    pub(crate) fn add_constraint(
+        &mut self,
+        predecessor: FlowNodeId,
+        test_expression: ExpressionId,
+    ) -> FlowNodeId {
+        self.add(FlowNode::Constraint(ConstraintFlowNode {
+            predecessor,
+            test_expression,
+        }))
+    }
+
+    pub(super) fn record_expr(&mut self, node_id: FlowNodeId) -> ExpressionId {
+        self.flow_graph.expression_map.push(node_id)
+    }
+
+    pub(super) fn finish(mut self) -> FlowGraph {
+        self.flow_graph.flow_nodes_by_id.shrink_to_fit();
+        self.flow_graph.expression_map.shrink_to_fit();
+        self.flow_graph
+    }
+}
+
+/// A definition, and the set of constraints between a use and the definition
+#[derive(Debug, Clone)]
+pub struct ConstrainedDefinition {
+    pub definition: Definition,
+    pub constraints: Vec<ExpressionId>,
+}
+
+/// A flow node and the constraints we passed through to reach it
+#[derive(Debug)]
+struct FlowState {
+    node_id: FlowNodeId,
+    constraints_range: Range<usize>,
+}
+
+#[derive(Debug)]
+pub struct ReachableDefinitionsIterator<'a> {
+    flow_graph: &'a FlowGraph,
+    symbol_id: SymbolId,
+    pending: Vec<FlowState>,
+    constraints: Vec<ExpressionId>,
+}
+
+impl<'a> ReachableDefinitionsIterator<'a> {
+    pub fn new(flow_graph: &'a FlowGraph, symbol_id: SymbolId, start_node_id: FlowNodeId) -> Self {
+        Self {
+            flow_graph,
+            symbol_id,
+            pending: vec![FlowState {
+                node_id: start_node_id,
+                constraints_range: 0..0,
+            }],
+            constraints: vec![],
+        }
+    }
+}
+
+impl<'a> Iterator for ReachableDefinitionsIterator<'a> {
+    type Item = ConstrainedDefinition;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let FlowState {
+            mut node_id,
+            mut constraints_range,
+        } = self.pending.pop()?;
+        self.constraints.truncate(constraints_range.end + 1);
+        loop {
+            match &self.flow_graph.flow_nodes_by_id[node_id] {
+                FlowNode::Start => {
+                    // constraints on unbound are irrelevant
+                    return Some(ConstrainedDefinition {
+                        definition: Definition::Unbound,
+                        constraints: vec![],
+                    });
+                }
+                FlowNode::Definition(def_node) => {
+                    if def_node.symbol_id == self.symbol_id {
+                        return Some(ConstrainedDefinition {
+                            definition: def_node.definition.clone(),
+                            constraints: self.constraints[constraints_range].to_vec(),
+                        });
+                    }
+                    node_id = def_node.predecessor;
+                }
+                FlowNode::Branch(branch_node) => {
+                    node_id = branch_node.predecessor;
+                }
+                FlowNode::Phi(phi_node) => {
+                    self.pending.push(FlowState {
+                        node_id: phi_node.first_predecessor,
+                        constraints_range: constraints_range.clone(),
+                    });
+                    node_id = phi_node.second_predecessor;
+                }
+                FlowNode::Constraint(constraint_node) => {
+                    node_id = constraint_node.predecessor;
+                    self.constraints.push(constraint_node.test_expression);
+                    constraints_range.end += 1;
+                }
+            }
+        }
+    }
+}
+
+impl<'a> FusedIterator for ReachableDefinitionsIterator<'a> {}
+
+impl std::fmt::Display for FlowGraph {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        writeln!(f, "flowchart TD")?;
+        for (id, node) in self.flow_nodes_by_id.iter_enumerated() {
+            write!(f, "  id{}", id.as_u32())?;
+            match node {
+                FlowNode::Start => writeln!(f, r"[\Start/]")?,
+                FlowNode::Definition(def_node) => {
+                    writeln!(f, r"(Define symbol {})", def_node.symbol_id.as_u32())?;
+                    writeln!(
+                        f,
+                        r"  id{}-->id{}",
+                        def_node.predecessor.as_u32(),
+                        id.as_u32()
+                    )?;
+                }
+                FlowNode::Branch(branch_node) => {
+                    writeln!(f, r"{{Branch}}")?;
+                    writeln!(
+                        f,
+                        r"  id{}-->id{}",
+                        branch_node.predecessor.as_u32(),
+                        id.as_u32()
+                    )?;
+                }
+                FlowNode::Phi(phi_node) => {
+                    writeln!(f, r"((Phi))")?;
+                    writeln!(
+                        f,
+                        r"  id{}-->id{}",
+                        phi_node.second_predecessor.as_u32(),
+                        id.as_u32()
+                    )?;
+                    writeln!(
+                        f,
+                        r"  id{}-->id{}",
+                        phi_node.first_predecessor.as_u32(),
+                        id.as_u32()
+                    )?;
+                }
+                FlowNode::Constraint(constraint_node) => {
+                    writeln!(f, r"((Constraint))")?;
+                    writeln!(
+                        f,
+                        r"  id{}-->id{}",
+                        constraint_node.predecessor.as_u32(),
+                        id.as_u32()
+                    )?;
+                }
+            }
+        }
+        Ok(())
+    }
+}

crates/red_knot/src/semantic/symbol_table.rs

@@ -0,0 +1,560 @@
+#![allow(dead_code)]
+
+use std::hash::{Hash, Hasher};
+use std::iter::{Copied, DoubleEndedIterator, FusedIterator};
+use std::num::NonZeroU32;
+
+use bitflags::bitflags;
+use hashbrown::hash_map::{Keys, RawEntryMut};
+use rustc_hash::{FxHashMap, FxHasher};
+
+use ruff_index::{newtype_index, IndexVec};
+
+use crate::ast_ids::NodeKey;
+use crate::module::ModuleName;
+use crate::semantic::{Definition, ExpressionId};
+use crate::Name;
+
+type Map<K, V> = hashbrown::HashMap<K, V, ()>;
+
+#[newtype_index]
+pub struct ScopeId;
+
+impl ScopeId {
+    pub fn scope(self, table: &SymbolTable) -> &Scope {
+        &table.scopes_by_id[self]
+    }
+}
+
+#[newtype_index]
+pub struct SymbolId;
+
+impl SymbolId {
+    pub fn symbol(self, table: &SymbolTable) -> &Symbol {
+        &table.symbols_by_id[self]
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum ScopeKind {
+    Module,
+    Annotation,
+    Class,
+    Function,
+}
+
+#[derive(Debug)]
+pub struct Scope {
+    name: Name,
+    kind: ScopeKind,
+    parent: Option<ScopeId>,
+    children: Vec<ScopeId>,
+    /// the definition (e.g. class or function) that created this scope
+    definition: Option<Definition>,
+    /// the symbol (e.g. class or function) that owns this scope
+    defining_symbol: Option<SymbolId>,
+    /// symbol IDs, hashed by symbol name
+    symbols_by_name: Map<SymbolId, ()>,
+}
+
+impl Scope {
+    pub fn name(&self) -> &str {
+        self.name.as_str()
+    }
+
+    pub fn kind(&self) -> ScopeKind {
+        self.kind
+    }
+
+    pub fn definition(&self) -> Option<Definition> {
+        self.definition.clone()
+    }
+
+    pub fn defining_symbol(&self) -> Option<SymbolId> {
+        self.defining_symbol
+    }
+}
+
+#[derive(Debug)]
+pub(crate) enum Kind {
+    FreeVar,
+    CellVar,
+    CellVarAssigned,
+    ExplicitGlobal,
+    ImplicitGlobal,
+}
+
+bitflags! {
+    #[derive(Copy,Clone,Debug)]
+    pub struct SymbolFlags: u8 {
+        const IS_USED         = 1 << 0;
+        const IS_DEFINED      = 1 << 1;
+        /// TODO: This flag is not yet set by anything
+        const MARKED_GLOBAL   = 1 << 2;
+        /// TODO: This flag is not yet set by anything
+        const MARKED_NONLOCAL = 1 << 3;
+    }
+}
+
+#[derive(Debug)]
+pub struct Symbol {
+    name: Name,
+    flags: SymbolFlags,
+    scope_id: ScopeId,
+    // kind: Kind,
+}
+
+impl Symbol {
+    pub fn name(&self) -> &str {
+        self.name.as_str()
+    }
+
+    pub fn scope_id(&self) -> ScopeId {
+        self.scope_id
+    }
+
+    /// Is the symbol used in its containing scope?
+    pub fn is_used(&self) -> bool {
+        self.flags.contains(SymbolFlags::IS_USED)
+    }
+
+    /// Is the symbol defined in its containing scope?
+    pub fn is_defined(&self) -> bool {
+        self.flags.contains(SymbolFlags::IS_DEFINED)
+    }
+
+    // TODO: implement Symbol.kind 2-pass analysis to categorize as: free-var, cell-var,
+    // explicit-global, implicit-global and implement Symbol.kind by modifying the preorder
+    // traversal code
+}
+
+#[derive(Debug, Clone)]
+pub enum Dependency {
+    Module(ModuleName),
+    Relative {
+        level: NonZeroU32,
+        module: Option<ModuleName>,
+    },
+}
+
+/// Table of all symbols in all scopes for a module.
+#[derive(Debug)]
+pub struct SymbolTable {
+    scopes_by_id: IndexVec<ScopeId, Scope>,
+    symbols_by_id: IndexVec<SymbolId, Symbol>,
+    /// the definitions for each symbol
+    defs: FxHashMap<SymbolId, Vec<Definition>>,
+    /// map of AST node (e.g. class/function def) to sub-scope it creates
+    scopes_by_node: FxHashMap<NodeKey, ScopeId>,
+    /// Maps expressions to their enclosing scope.
+    expression_scopes: IndexVec<ExpressionId, ScopeId>,
+    /// dependencies of this module
+    dependencies: Vec<Dependency>,
+}
+
+impl SymbolTable {
+    pub fn dependencies(&self) -> &[Dependency] {
+        &self.dependencies
+    }
+
+    pub const fn root_scope_id() -> ScopeId {
+        ScopeId::from_usize(0)
+    }
+
+    pub fn root_scope(&self) -> &Scope {
+        &self.scopes_by_id[SymbolTable::root_scope_id()]
+    }
+
+    pub fn symbol_ids_for_scope(&self, scope_id: ScopeId) -> Copied<Keys<SymbolId, ()>> {
+        self.scopes_by_id[scope_id].symbols_by_name.keys().copied()
+    }
+
+    pub fn symbols_for_scope(
+        &self,
+        scope_id: ScopeId,
+    ) -> SymbolIterator<Copied<Keys<SymbolId, ()>>> {
+        SymbolIterator {
+            table: self,
+            ids: self.symbol_ids_for_scope(scope_id),
+        }
+    }
+
+    pub fn root_symbol_ids(&self) -> Copied<Keys<SymbolId, ()>> {
+        self.symbol_ids_for_scope(SymbolTable::root_scope_id())
+    }
+
+    pub fn root_symbols(&self) -> SymbolIterator<Copied<Keys<SymbolId, ()>>> {
+        self.symbols_for_scope(SymbolTable::root_scope_id())
+    }
+
+    pub fn child_scope_ids_of(&self, scope_id: ScopeId) -> &[ScopeId] {
+        &self.scopes_by_id[scope_id].children
+    }
+
+    pub fn child_scopes_of(&self, scope_id: ScopeId) -> ScopeIterator<&[ScopeId]> {
+        ScopeIterator {
+            table: self,
+            ids: self.child_scope_ids_of(scope_id),
+        }
+    }
+
+    pub fn root_child_scope_ids(&self) -> &[ScopeId] {
+        self.child_scope_ids_of(SymbolTable::root_scope_id())
+    }
+
+    pub fn root_child_scopes(&self) -> ScopeIterator<&[ScopeId]> {
+        self.child_scopes_of(SymbolTable::root_scope_id())
+    }
+
+    pub fn symbol_id_by_name(&self, scope_id: ScopeId, name: &str) -> Option<SymbolId> {
+        let scope = &self.scopes_by_id[scope_id];
+        let hash = SymbolTable::hash_name(name);
+        let name = Name::new(name);
+        Some(
+            *scope
+                .symbols_by_name
+                .raw_entry()
+                .from_hash(hash, |symid| self.symbols_by_id[*symid].name == name)?
+                .0,
+        )
+    }
+
+    pub fn symbol_by_name(&self, scope_id: ScopeId, name: &str) -> Option<&Symbol> {
+        Some(&self.symbols_by_id[self.symbol_id_by_name(scope_id, name)?])
+    }
+
+    pub fn root_symbol_id_by_name(&self, name: &str) -> Option<SymbolId> {
+        self.symbol_id_by_name(SymbolTable::root_scope_id(), name)
+    }
+
+    pub fn root_symbol_by_name(&self, name: &str) -> Option<&Symbol> {
+        self.symbol_by_name(SymbolTable::root_scope_id(), name)
+    }
+
+    pub fn scope_id_of_symbol(&self, symbol_id: SymbolId) -> ScopeId {
+        self.symbols_by_id[symbol_id].scope_id
+    }
+
+    pub fn scope_of_symbol(&self, symbol_id: SymbolId) -> &Scope {
+        &self.scopes_by_id[self.scope_id_of_symbol(symbol_id)]
+    }
+
+    pub fn scope_id_of_expression(&self, expression: ExpressionId) -> ScopeId {
+        self.expression_scopes[expression]
+    }
+
+    pub fn scope_of_expression(&self, expr_id: ExpressionId) -> &Scope {
+        &self.scopes_by_id[self.scope_id_of_expression(expr_id)]
+    }
+
+    pub fn parent_scopes(
+        &self,
+        scope_id: ScopeId,
+    ) -> ScopeIterator<impl Iterator<Item = ScopeId> + '_> {
+        ScopeIterator {
+            table: self,
+            ids: std::iter::successors(Some(scope_id), |scope| self.scopes_by_id[*scope].parent),
+        }
+    }
+
+    pub fn parent_scope(&self, scope_id: ScopeId) -> Option<ScopeId> {
+        self.scopes_by_id[scope_id].parent
+    }
+
+    pub fn scope_id_for_node(&self, node_key: &NodeKey) -> ScopeId {
+        self.scopes_by_node[node_key]
+    }
+
+    pub fn definitions(&self, symbol_id: SymbolId) -> &[Definition] {
+        self.defs
+            .get(&symbol_id)
+            .map(std::vec::Vec::as_slice)
+            .unwrap_or_default()
+    }
+
+    pub fn all_definitions(&self) -> impl Iterator<Item = (SymbolId, &Definition)> + '_ {
+        self.defs
+            .iter()
+            .flat_map(|(sym_id, defs)| defs.iter().map(move |def| (*sym_id, def)))
+    }
+
+    fn hash_name(name: &str) -> u64 {
+        let mut hasher = FxHasher::default();
+        name.hash(&mut hasher);
+        hasher.finish()
+    }
+}
+
+pub struct SymbolIterator<'a, I> {
+    table: &'a SymbolTable,
+    ids: I,
+}
+
+impl<'a, I> Iterator for SymbolIterator<'a, I>
+where
+    I: Iterator<Item = SymbolId>,
+{
+    type Item = &'a Symbol;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let id = self.ids.next()?;
+        Some(&self.table.symbols_by_id[id])
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.ids.size_hint()
+    }
+}
+
+impl<'a, I> FusedIterator for SymbolIterator<'a, I> where
+    I: Iterator<Item = SymbolId> + FusedIterator
+{
+}
+
+impl<'a, I> DoubleEndedIterator for SymbolIterator<'a, I>
+where
+    I: Iterator<Item = SymbolId> + DoubleEndedIterator,
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        let id = self.ids.next_back()?;
+        Some(&self.table.symbols_by_id[id])
+    }
+}
+
+// TODO maybe get rid of this and just do all data access via methods on ScopeId?
+pub struct ScopeIterator<'a, I> {
+    table: &'a SymbolTable,
+    ids: I,
+}
+
+/// iterate (`ScopeId`, `Scope`) pairs for given `ScopeId` iterator
+impl<'a, I> Iterator for ScopeIterator<'a, I>
+where
+    I: Iterator<Item = ScopeId>,
+{
+    type Item = (ScopeId, &'a Scope);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let id = self.ids.next()?;
+        Some((id, &self.table.scopes_by_id[id]))
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.ids.size_hint()
+    }
+}
+
+impl<'a, I> FusedIterator for ScopeIterator<'a, I> where I: Iterator<Item = ScopeId> + FusedIterator {}
+
+impl<'a, I> DoubleEndedIterator for ScopeIterator<'a, I>
+where
+    I: Iterator<Item = ScopeId> + DoubleEndedIterator,
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        let id = self.ids.next_back()?;
+        Some((id, &self.table.scopes_by_id[id]))
+    }
+}
+
+#[derive(Debug)]
+pub(super) struct SymbolTableBuilder {
+    symbol_table: SymbolTable,
+}
+
+impl SymbolTableBuilder {
+    pub(super) fn new() -> Self {
+        let mut table = SymbolTable {
+            scopes_by_id: IndexVec::new(),
+            symbols_by_id: IndexVec::new(),
+            defs: FxHashMap::default(),
+            scopes_by_node: FxHashMap::default(),
+            expression_scopes: IndexVec::new(),
+            dependencies: Vec::new(),
+        };
+        table.scopes_by_id.push(Scope {
+            name: Name::new("<module>"),
+            kind: ScopeKind::Module,
+            parent: None,
+            children: Vec::new(),
+            definition: None,
+            defining_symbol: None,
+            symbols_by_name: Map::default(),
+        });
+        Self {
+            symbol_table: table,
+        }
+    }
+
+    pub(super) fn finish(self) -> SymbolTable {
+        let mut symbol_table = self.symbol_table;
+        symbol_table.scopes_by_id.shrink_to_fit();
+        symbol_table.symbols_by_id.shrink_to_fit();
+        symbol_table.defs.shrink_to_fit();
+        symbol_table.scopes_by_node.shrink_to_fit();
+        symbol_table.expression_scopes.shrink_to_fit();
+        symbol_table.dependencies.shrink_to_fit();
+        symbol_table
+    }
+
+    pub(super) fn add_or_update_symbol(
+        &mut self,
+        scope_id: ScopeId,
+        name: &str,
+        flags: SymbolFlags,
+    ) -> SymbolId {
+        let hash = SymbolTable::hash_name(name);
+        let scope = &mut self.symbol_table.scopes_by_id[scope_id];
+        let name = Name::new(name);
+
+        let entry = scope
+            .symbols_by_name
+            .raw_entry_mut()
+            .from_hash(hash, |existing| {
+                self.symbol_table.symbols_by_id[*existing].name == name
+            });
+
+        match entry {
+            RawEntryMut::Occupied(entry) => {
+                if let Some(symbol) = self.symbol_table.symbols_by_id.get_mut(*entry.key()) {
+                    symbol.flags.insert(flags);
+                };
+                *entry.key()
+            }
+            RawEntryMut::Vacant(entry) => {
+                let id = self.symbol_table.symbols_by_id.push(Symbol {
+                    name,
+                    flags,
+                    scope_id,
+                });
+                entry.insert_with_hasher(hash, id, (), |symid| {
+                    SymbolTable::hash_name(&self.symbol_table.symbols_by_id[*symid].name)
+                });
+                id
+            }
+        }
+    }
+
+    pub(super) fn add_definition(&mut self, symbol_id: SymbolId, definition: Definition) {
+        self.symbol_table
+            .defs
+            .entry(symbol_id)
+            .or_default()
+            .push(definition);
+    }
+
+    pub(super) fn add_child_scope(
+        &mut self,
+        parent_scope_id: ScopeId,
+        name: &str,
+        kind: ScopeKind,
+        definition: Option<Definition>,
+        defining_symbol: Option<SymbolId>,
+    ) -> ScopeId {
+        let new_scope_id = self.symbol_table.scopes_by_id.push(Scope {
+            name: Name::new(name),
+            kind,
+            parent: Some(parent_scope_id),
+            children: Vec::new(),
+            definition,
+            defining_symbol,
+            symbols_by_name: Map::default(),
+        });
+        let parent_scope = &mut self.symbol_table.scopes_by_id[parent_scope_id];
+        parent_scope.children.push(new_scope_id);
+        new_scope_id
+    }
+
+    pub(super) fn record_scope_for_node(&mut self, node_key: NodeKey, scope_id: ScopeId) {
+        self.symbol_table.scopes_by_node.insert(node_key, scope_id);
+    }
+
+    pub(super) fn add_dependency(&mut self, dependency: Dependency) {
+        self.symbol_table.dependencies.push(dependency);
+    }
+
+    /// Records the scope for the current expression
+    pub(super) fn record_expression(&mut self, scope: ScopeId) -> ExpressionId {
+        self.symbol_table.expression_scopes.push(scope)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{ScopeKind, SymbolFlags, SymbolTable, SymbolTableBuilder};
+
+    #[test]
+    fn insert_same_name_symbol_twice() {
+        let mut builder = SymbolTableBuilder::new();
+        let root_scope_id = SymbolTable::root_scope_id();
+        let symbol_id_1 =
+            builder.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::IS_DEFINED);
+        let symbol_id_2 = builder.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::IS_USED);
+        let table = builder.finish();
+
+        assert_eq!(symbol_id_1, symbol_id_2);
+        assert!(symbol_id_1.symbol(&table).is_used(), "flags must merge");
+        assert!(symbol_id_1.symbol(&table).is_defined(), "flags must merge");
+    }
+
+    #[test]
+    fn insert_different_named_symbols() {
+        let mut builder = SymbolTableBuilder::new();
+        let root_scope_id = SymbolTable::root_scope_id();
+        let symbol_id_1 = builder.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::empty());
+        let symbol_id_2 = builder.add_or_update_symbol(root_scope_id, "bar", SymbolFlags::empty());
+
+        assert_ne!(symbol_id_1, symbol_id_2);
+    }
+
+    #[test]
+    fn add_child_scope_with_symbol() {
+        let mut builder = SymbolTableBuilder::new();
+        let root_scope_id = SymbolTable::root_scope_id();
+        let foo_symbol_top =
+            builder.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::empty());
+        let c_scope = builder.add_child_scope(root_scope_id, "C", ScopeKind::Class, None, None);
+        let foo_symbol_inner = builder.add_or_update_symbol(c_scope, "foo", SymbolFlags::empty());
+
+        assert_ne!(foo_symbol_top, foo_symbol_inner);
+    }
+
+    #[test]
+    fn scope_from_id() {
+        let table = SymbolTableBuilder::new().finish();
+        let root_scope_id = SymbolTable::root_scope_id();
+        let scope = root_scope_id.scope(&table);
+
+        assert_eq!(scope.name.as_str(), "<module>");
+        assert_eq!(scope.kind, ScopeKind::Module);
+    }
+
+    #[test]
+    fn symbol_from_id() {
+        let mut builder = SymbolTableBuilder::new();
+        let root_scope_id = SymbolTable::root_scope_id();
+        let foo_symbol_id =
+            builder.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::empty());
+        let table = builder.finish();
+        let symbol = foo_symbol_id.symbol(&table);
+
+        assert_eq!(symbol.name(), "foo");
+    }
+
+    #[test]
+    fn bigger_symbol_table() {
+        let mut builder = SymbolTableBuilder::new();
+        let root_scope_id = SymbolTable::root_scope_id();
+        let foo_symbol_id =
+            builder.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::empty());
+        builder.add_or_update_symbol(root_scope_id, "bar", SymbolFlags::empty());
+        builder.add_or_update_symbol(root_scope_id, "baz", SymbolFlags::empty());
+        builder.add_or_update_symbol(root_scope_id, "qux", SymbolFlags::empty());
+        let table = builder.finish();
+
+        let foo_symbol_id_2 = table
+            .root_symbol_id_by_name("foo")
+            .expect("foo symbol to be found");
+
+        assert_eq!(foo_symbol_id_2, foo_symbol_id);
+    }
+}

crates/red_knot/src/semantic/types/infer.rs

@@ -0,0 +1,762 @@
+#![allow(dead_code)]
+
+use ruff_python_ast as ast;
+use ruff_python_ast::AstNode;
+use std::fmt::Debug;
+
+use crate::db::{QueryResult, SemanticDb, SemanticJar};
+
+use crate::module::{resolve_module, ModuleName};
+use crate::parse::parse;
+use crate::semantic::types::{ModuleTypeId, Type};
+use crate::semantic::{
+    resolve_global_symbol, semantic_index, ConstrainedDefinition, Definition, GlobalSymbolId,
+    ImportDefinition, ImportFromDefinition,
+};
+use crate::{FileId, Name};
+
+// FIXME: Figure out proper dead-lock free synchronisation now that this takes `&db` instead of `&mut db`.
+/// Resolve the public-facing type for a symbol (the type seen by other scopes: other modules, or
+/// nested functions). Because calls to nested functions and imports can occur anywhere in control
+/// flow, this type must be conservative and consider all definitions of the symbol that could
+/// possibly be seen by another scope. Currently we take the most conservative approach, which is
+/// the union of all definitions. We may be able to narrow this in future to eliminate definitions
+/// which can't possibly (or at least likely) be seen by any other scope, so that e.g. we could
+/// infer `Literal["1"]` instead of `Literal[1] | Literal["1"]` for `x` in `x = x; x = str(x);`.
+#[tracing::instrument(level = "trace", skip(db))]
+pub fn infer_symbol_public_type(db: &dyn SemanticDb, symbol: GlobalSymbolId) -> QueryResult<Type> {
+    let index = semantic_index(db, symbol.file_id)?;
+    let defs = index.symbol_table().definitions(symbol.symbol_id).to_vec();
+    let jar: &SemanticJar = db.jar()?;
+
+    if let Some(ty) = jar.type_store.get_cached_symbol_public_type(symbol) {
+        return Ok(ty);
+    }
+
+    let ty = infer_type_from_definitions(db, symbol, defs.iter().cloned())?;
+
+    jar.type_store.cache_symbol_public_type(symbol, ty);
+
+    // TODO record dependencies
+    Ok(ty)
+}
+
+/// Infer type of a symbol as union of the given `Definitions`.
+fn infer_type_from_definitions<T>(
+    db: &dyn SemanticDb,
+    symbol: GlobalSymbolId,
+    definitions: T,
+) -> QueryResult<Type>
+where
+    T: Debug + IntoIterator<Item = Definition>,
+{
+    infer_type_from_constrained_definitions(
+        db,
+        symbol,
+        definitions
+            .into_iter()
+            .map(|definition| ConstrainedDefinition {
+                definition,
+                constraints: vec![],
+            }),
+    )
+}
+
+/// Infer type of a symbol as union of the given `ConstrainedDefinitions`.
+fn infer_type_from_constrained_definitions<T>(
+    db: &dyn SemanticDb,
+    symbol: GlobalSymbolId,
+    constrained_definitions: T,
+) -> QueryResult<Type>
+where
+    T: IntoIterator<Item = ConstrainedDefinition>,
+{
+    let jar: &SemanticJar = db.jar()?;
+    let mut tys = constrained_definitions
+        .into_iter()
+        .map(|def| infer_constrained_definition_type(db, symbol, def.clone()))
+        .peekable();
+    if let Some(first) = tys.next() {
+        if tys.peek().is_some() {
+            Ok(jar.type_store.add_union(
+                symbol.file_id,
+                &Iterator::chain(std::iter::once(first), tys).collect::<QueryResult<Vec<_>>>()?,
+            ))
+        } else {
+            first
+        }
+    } else {
+        Ok(Type::Unknown)
+    }
+}
+
+/// Infer type for a ConstrainedDefinition (intersection of the definition type and the
+/// constraints)
+#[tracing::instrument(level = "trace", skip(db))]
+pub fn infer_constrained_definition_type(
+    db: &dyn SemanticDb,
+    symbol: GlobalSymbolId,
+    constrained_definition: ConstrainedDefinition,
+) -> QueryResult<Type> {
+    let ConstrainedDefinition {
+        definition,
+        constraints,
+    } = constrained_definition;
+    let index = semantic_index(db, symbol.file_id)?;
+    let parsed = parse(db.upcast(), symbol.file_id)?;
+    let mut intersected_types = vec![infer_definition_type(db, symbol, definition)?];
+    for constraint in constraints {
+        if let Some(constraint_type) = infer_constraint_type(
+            db,
+            symbol,
+            index.resolve_expression_id(parsed.syntax(), constraint),
+        )? {
+            intersected_types.push(constraint_type);
+        }
+    }
+    let jar: &SemanticJar = db.jar()?;
+    Ok(jar
+        .type_store
+        .add_intersection(symbol.file_id, &intersected_types, &[]))
+}
+
+/// Infer a type for a Definition
+#[tracing::instrument(level = "trace", skip(db))]
+pub fn infer_definition_type(
+    db: &dyn SemanticDb,
+    symbol: GlobalSymbolId,
+    definition: Definition,
+) -> QueryResult<Type> {
+    let jar: &SemanticJar = db.jar()?;
+    let type_store = &jar.type_store;
+    let file_id = symbol.file_id;
+
+    match definition {
+        Definition::Unbound => Ok(Type::Unbound),
+        Definition::Import(ImportDefinition {
+            module: module_name,
+        }) => {
+            if let Some(module) = resolve_module(db, module_name.clone())? {
+                Ok(Type::Module(ModuleTypeId { module, file_id }))
+            } else {
+                Ok(Type::Unknown)
+            }
+        }
+        Definition::ImportFrom(ImportFromDefinition {
+            module,
+            name,
+            level,
+        }) => {
+            // TODO relative imports
+            assert!(matches!(level, 0));
+            let module_name = ModuleName::new(module.as_ref().expect("TODO relative imports"));
+            let Some(module) = resolve_module(db, module_name.clone())? else {
+                return Ok(Type::Unknown);
+            };
+
+            if let Some(remote_symbol) = resolve_global_symbol(db, module, &name)? {
+                infer_symbol_public_type(db, remote_symbol)
+            } else {
+                Ok(Type::Unknown)
+            }
+        }
+        Definition::ClassDef(node_key) => {
+            if let Some(ty) = type_store.get_cached_node_type(file_id, node_key.erased()) {
+                Ok(ty)
+            } else {
+                let parsed = parse(db.upcast(), file_id)?;
+                let ast = parsed.syntax();
+                let index = semantic_index(db, file_id)?;
+                let node = node_key.resolve_unwrap(ast.as_any_node_ref());
+
+                let mut bases = Vec::with_capacity(node.bases().len());
+
+                for base in node.bases() {
+                    bases.push(infer_expr_type(db, file_id, base)?);
+                }
+                let scope_id = index.symbol_table().scope_id_for_node(node_key.erased());
+                let ty = type_store.add_class(file_id, &node.name.id, scope_id, bases);
+                type_store.cache_node_type(file_id, *node_key.erased(), ty);
+                Ok(ty)
+            }
+        }
+        Definition::FunctionDef(node_key) => {
+            if let Some(ty) = type_store.get_cached_node_type(file_id, node_key.erased()) {
+                Ok(ty)
+            } else {
+                let parsed = parse(db.upcast(), file_id)?;
+                let ast = parsed.syntax();
+                let index = semantic_index(db, file_id)?;
+                let node = node_key
+                    .resolve(ast.as_any_node_ref())
+                    .expect("node key should resolve");
+
+                let decorator_tys = node
+                    .decorator_list
+                    .iter()
+                    .map(|decorator| infer_expr_type(db, file_id, &decorator.expression))
+                    .collect::<QueryResult<_>>()?;
+                let scope_id = index.symbol_table().scope_id_for_node(node_key.erased());
+                let ty = type_store.add_function(
+                    file_id,
+                    &node.name.id,
+                    symbol.symbol_id,
+                    scope_id,
+                    decorator_tys,
+                );
+                type_store.cache_node_type(file_id, *node_key.erased(), ty);
+                Ok(ty)
+            }
+        }
+        Definition::Assignment(node_key) => {
+            let parsed = parse(db.upcast(), file_id)?;
+            let ast = parsed.syntax();
+            let node = node_key.resolve_unwrap(ast.as_any_node_ref());
+            // TODO handle unpacking assignment
+            infer_expr_type(db, file_id, &node.value)
+        }
+        Definition::AnnotatedAssignment(node_key) => {
+            let parsed = parse(db.upcast(), file_id)?;
+            let ast = parsed.syntax();
+            let node = node_key.resolve_unwrap(ast.as_any_node_ref());
+            // TODO actually look at the annotation
+            let Some(value) = &node.value else {
+                return Ok(Type::Unknown);
+            };
+            // TODO handle unpacking assignment
+            infer_expr_type(db, file_id, value)
+        }
+        Definition::NamedExpr(node_key) => {
+            let parsed = parse(db.upcast(), file_id)?;
+            let ast = parsed.syntax();
+            let node = node_key.resolve_unwrap(ast.as_any_node_ref());
+            infer_expr_type(db, file_id, &node.value)
+        }
+    }
+}
+
+/// Return the type that the given constraint (an expression from a control-flow test) requires the
+/// given symbol to have. For example, returns the Type "~None" as the constraint type if given the
+/// symbol ID for x and the expression ID for `x is not None`. Returns (Rust) None if the given
+/// expression applies no constraints on the given symbol.
+#[tracing::instrument(level = "trace", skip(db))]
+fn infer_constraint_type(
+    db: &dyn SemanticDb,
+    symbol_id: GlobalSymbolId,
+    // TODO this should preferably take an &ast::Expr instead of AnyNodeRef
+    expression: ast::AnyNodeRef,
+) -> QueryResult<Option<Type>> {
+    let file_id = symbol_id.file_id;
+    let index = semantic_index(db, file_id)?;
+    let jar: &SemanticJar = db.jar()?;
+    let symbol_name = symbol_id.symbol_id.symbol(&index.symbol_table).name();
+    // TODO narrowing attributes
+    // TODO narrowing dict keys
+    // TODO isinstance, ==/!=, type(...), literals, bools...
+    match expression {
+        ast::AnyNodeRef::ExprCompare(ast::ExprCompare {
+            left,
+            ops,
+            comparators,
+            ..
+        }) => {
+            // TODO chained comparisons
+            match left.as_ref() {
+                ast::Expr::Name(ast::ExprName { id, .. }) if id == symbol_name => match ops[0] {
+                    ast::CmpOp::Is | ast::CmpOp::IsNot => {
+                        Ok(match infer_expr_type(db, file_id, &comparators[0])? {
+                            Type::None => Some(Type::None),
+                            _ => None,
+                        }
+                        .map(|ty| {
+                            if matches!(ops[0], ast::CmpOp::IsNot) {
+                                jar.type_store.add_intersection(file_id, &[], &[ty])
+                            } else {
+                                ty
+                            }
+                        }))
+                    }
+                    _ => Ok(None),
+                },
+                _ => Ok(None),
+            }
+        }
+        _ => Ok(None),
+    }
+}
+
+/// Infer type of the given expression.
+fn infer_expr_type(db: &dyn SemanticDb, file_id: FileId, expr: &ast::Expr) -> QueryResult<Type> {
+    // TODO cache the resolution of the type on the node
+    let index = semantic_index(db, file_id)?;
+    match expr {
+        ast::Expr::NoneLiteral(_) => Ok(Type::None),
+        ast::Expr::NumberLiteral(ast::ExprNumberLiteral { value, .. }) => {
+            match value {
+                ast::Number::Int(n) => {
+                    // TODO support big int literals
+                    Ok(n.as_i64().map(Type::IntLiteral).unwrap_or(Type::Unknown))
+                }
+                // TODO builtins.float or builtins.complex
+                _ => Ok(Type::Unknown),
+            }
+        }
+        ast::Expr::Name(name) => {
+            // TODO look up in the correct scope, don't assume global
+            if let Some(symbol_id) = index.symbol_table().root_symbol_id_by_name(&name.id) {
+                infer_type_from_constrained_definitions(
+                    db,
+                    GlobalSymbolId { file_id, symbol_id },
+                    index.reachable_definitions(symbol_id, expr),
+                )
+            } else {
+                Ok(Type::Unknown)
+            }
+        }
+        ast::Expr::Attribute(ast::ExprAttribute { value, attr, .. }) => {
+            let value_type = infer_expr_type(db, file_id, value)?;
+            let attr_name = &Name::new(&attr.id);
+            value_type
+                .get_member(db, attr_name)
+                .map(|ty| ty.unwrap_or(Type::Unknown))
+        }
+        ast::Expr::BinOp(ast::ExprBinOp {
+            left, op, right, ..
+        }) => {
+            let left_ty = infer_expr_type(db, file_id, left)?;
+            let right_ty = infer_expr_type(db, file_id, right)?;
+            // TODO add reverse bin op support if right <: left
+            left_ty.resolve_bin_op(db, *op, right_ty)
+        }
+        ast::Expr::Named(ast::ExprNamed { value, .. }) => infer_expr_type(db, file_id, value),
+        ast::Expr::If(ast::ExprIf { body, orelse, .. }) => {
+            // TODO detect statically known truthy or falsy test
+            let body_ty = infer_expr_type(db, file_id, body)?;
+            let else_ty = infer_expr_type(db, file_id, orelse)?;
+            let jar: &SemanticJar = db.jar()?;
+            Ok(jar.type_store.add_union(file_id, &[body_ty, else_ty]))
+        }
+        _ => todo!("expression type resolution for {:?}", expr),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use std::path::PathBuf;
+
+    use crate::db::tests::TestDb;
+    use crate::db::{HasJar, SemanticJar};
+    use crate::module::{
+        resolve_module, set_module_search_paths, ModuleName, ModuleResolutionInputs,
+    };
+    use crate::semantic::{infer_symbol_public_type, resolve_global_symbol, Type};
+    use crate::Name;
+
+    // TODO with virtual filesystem we shouldn't have to write files to disk for these
+    // tests
+
+    struct TestCase {
+        temp_dir: tempfile::TempDir,
+        db: TestDb,
+
+        src: PathBuf,
+    }
+
+    fn create_test() -> std::io::Result<TestCase> {
+        let temp_dir = tempfile::tempdir()?;
+
+        let src = temp_dir.path().join("src");
+        std::fs::create_dir(&src)?;
+        let src = src.canonicalize()?;
+
+        let search_paths = ModuleResolutionInputs {
+            extra_paths: vec![],
+            workspace_root: src.clone(),
+            site_packages: None,
+            custom_typeshed: None,
+        };
+
+        let mut db = TestDb::default();
+        set_module_search_paths(&mut db, search_paths);
+
+        Ok(TestCase { temp_dir, db, src })
+    }
+
+    fn write_to_path(case: &TestCase, relative_path: &str, contents: &str) -> anyhow::Result<()> {
+        let path = case.src.join(relative_path);
+        std::fs::write(path, contents)?;
+        Ok(())
+    }
+
+    fn get_public_type(
+        case: &TestCase,
+        module_name: &str,
+        variable_name: &str,
+    ) -> anyhow::Result<Type> {
+        let db = &case.db;
+        let module = resolve_module(db, ModuleName::new(module_name))?.expect("Module to exist");
+        let symbol = resolve_global_symbol(db, module, variable_name)?.expect("symbol to exist");
+
+        Ok(infer_symbol_public_type(db, symbol)?)
+    }
+
+    fn assert_public_type(
+        case: &TestCase,
+        module_name: &str,
+        variable_name: &str,
+        type_name: &str,
+    ) -> anyhow::Result<()> {
+        let ty = get_public_type(case, module_name, variable_name)?;
+
+        let jar = HasJar::<SemanticJar>::jar(&case.db)?;
+        assert_eq!(format!("{}", ty.display(&jar.type_store)), type_name);
+        Ok(())
+    }
+
+    #[test]
+    fn follow_import_to_class() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(&case, "a.py", "from b import C as D; E = D")?;
+        write_to_path(&case, "b.py", "class C: pass")?;
+
+        assert_public_type(&case, "a", "E", "Literal[C]")
+    }
+
+    #[test]
+    fn resolve_base_class_by_name() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "mod.py",
+            "
+                class Base: pass
+                class Sub(Base): pass
+            ",
+        )?;
+
+        let ty = get_public_type(&case, "mod", "Sub")?;
+
+        let Type::Class(class_id) = ty else {
+            panic!("Sub is not a Class")
+        };
+        let jar = HasJar::<SemanticJar>::jar(&case.db)?;
+        let base_names: Vec<_> = jar
+            .type_store
+            .get_class(class_id)
+            .bases()
+            .iter()
+            .map(|base_ty| format!("{}", base_ty.display(&jar.type_store)))
+            .collect();
+
+        assert_eq!(base_names, vec!["Literal[Base]"]);
+
+        Ok(())
+    }
+
+    #[test]
+    fn resolve_method() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "mod.py",
+            "
+                class C:
+                    def f(self): pass
+            ",
+        )?;
+
+        let ty = get_public_type(&case, "mod", "C")?;
+
+        let Type::Class(class_id) = ty else {
+            panic!("C is not a Class");
+        };
+
+        let member_ty = class_id
+            .get_own_class_member(&case.db, &Name::new("f"))
+            .expect("C.f to resolve");
+
+        let Some(Type::Function(func_id)) = member_ty else {
+            panic!("C.f is not a Function");
+        };
+
+        let jar = HasJar::<SemanticJar>::jar(&case.db)?;
+        let function = jar.type_store.get_function(func_id);
+        assert_eq!(function.name(), "f");
+
+        Ok(())
+    }
+
+    #[test]
+    fn resolve_module_member() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(&case, "a.py", "import b; D = b.C")?;
+        write_to_path(&case, "b.py", "class C: pass")?;
+
+        assert_public_type(&case, "a", "D", "Literal[C]")
+    }
+
+    #[test]
+    fn resolve_literal() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(&case, "a.py", "x = 1")?;
+
+        assert_public_type(&case, "a", "x", "Literal[1]")
+    }
+
+    #[test]
+    fn resolve_union() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                if flag:
+                    x = 1
+                else:
+                    x = 2
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "x", "Literal[1, 2]")
+    }
+
+    #[test]
+    fn resolve_visible_def() -> anyhow::Result<()> {
+        let case = create_test()?;
+        write_to_path(&case, "a.py", "y = 1; y = 2; x = y")?;
+        assert_public_type(&case, "a", "x", "Literal[2]")
+    }
+
+    #[test]
+    fn join_paths() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                y = 1
+                y = 2
+                if flag:
+                    y = 3
+                x = y
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "x", "Literal[2, 3]")
+    }
+
+    #[test]
+    fn maybe_unbound() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                if flag:
+                    y = 1
+                x = y
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "x", "Literal[1] | Unbound")
+    }
+
+    #[test]
+    fn if_elif_else() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                y = 1
+                y = 2
+                if flag:
+                    y = 3
+                elif flag2:
+                    y = 4
+                else:
+                    r = y
+                    y = 5
+                    s = y
+                x = y
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "x", "Literal[3, 4, 5]")?;
+        assert_public_type(&case, "a", "r", "Literal[2]")?;
+        assert_public_type(&case, "a", "s", "Literal[5]")
+    }
+
+    #[test]
+    fn if_elif() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                y = 1
+                y = 2
+                if flag:
+                    y = 3
+                elif flag2:
+                    y = 4
+                x = y
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "x", "Literal[2, 3, 4]")
+    }
+
+    #[test]
+    fn literal_int_arithmetic() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                a = 2 + 1
+                b = a - 4
+                c = a * b
+                d = c / 3
+                e = 5 % 3
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "a", "Literal[3]")?;
+        assert_public_type(&case, "a", "b", "Literal[-1]")?;
+        assert_public_type(&case, "a", "c", "Literal[-3]")?;
+        assert_public_type(&case, "a", "d", "Literal[-1]")?;
+        assert_public_type(&case, "a", "e", "Literal[2]")
+    }
+
+    #[test]
+    fn walrus() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                x = (y := 1) + 1
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "x", "Literal[2]")?;
+        assert_public_type(&case, "a", "y", "Literal[1]")
+    }
+
+    #[test]
+    fn ifexpr() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                x = 1 if flag else 2
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "x", "Literal[1, 2]")
+    }
+
+    #[test]
+    fn ifexpr_walrus() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                y = z = 0
+                x = (y := 1) if flag else (z := 2)
+                a = y
+                b = z
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "x", "Literal[1, 2]")?;
+        assert_public_type(&case, "a", "a", "Literal[0, 1]")?;
+        assert_public_type(&case, "a", "b", "Literal[0, 2]")
+    }
+
+    #[test]
+    fn ifexpr_walrus_2() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                y = 0
+                (y := 1) if flag else (y := 2)
+                a = y
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "a", "Literal[1, 2]")
+    }
+
+    #[test]
+    fn ifexpr_nested() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                x = 1 if flag else 2 if flag2 else 3
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "x", "Literal[1, 2, 3]")
+    }
+
+    #[test]
+    fn none() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                x = 1 if flag else None
+            ",
+        )?;
+
+        assert_public_type(&case, "a", "x", "Literal[1] | None")
+    }
+
+    #[test]
+    fn narrow_none() -> anyhow::Result<()> {
+        let case = create_test()?;
+
+        write_to_path(
+            &case,
+            "a.py",
+            "
+                x = 1 if flag else None
+                y = 0
+                if x is not None:
+                    y = x
+                z = y
+            ",
+        )?;
+
+        // TODO normalization of unions and intersections: this type is technically correct but
+        // begging for normalization
+        assert_public_type(&case, "a", "z", "Literal[0] | Literal[1] | None & ~None")
+    }
+}

crates/red_knot/src/source.rs

@@ -1,18 +1,17 @@
-use crate::cache::KeyValueCache;
-use crate::db::{HasJar, QueryResult, SourceDb, SourceJar};
-use ruff_notebook::Notebook;
-use ruff_python_ast::PySourceType;
 use std::ops::{Deref, DerefMut};
 use std::sync::Arc;
 
+use ruff_notebook::Notebook;
+use ruff_python_ast::PySourceType;
+
+use crate::cache::KeyValueCache;
+use crate::db::{QueryResult, SourceDb};
 use crate::files::FileId;
 
 #[tracing::instrument(level = "debug", skip(db))]
-pub(crate) fn source_text<Db>(db: &Db, file_id: FileId) -> QueryResult<Source>
-where
-    Db: SourceDb + HasJar<SourceJar>,
-{
-    let sources = &db.jar()?.sources;
+pub(crate) fn source_text(db: &dyn SourceDb, file_id: FileId) -> QueryResult<Source> {
+    let jar = db.jar()?;
+    let sources = &jar.sources;
 
     sources.get(&file_id, |file_id| {
         let path = db.file_path(*file_id);
@@ -54,6 +53,16 @@ pub enum SourceKind {
     IpyNotebook(Arc<Notebook>),
 }
 
+impl<'a> From<&'a SourceKind> for PySourceType {
+    fn from(value: &'a SourceKind) -> Self {
+        match value {
+            SourceKind::Python(_) => PySourceType::Python,
+            SourceKind::Stub(_) => PySourceType::Stub,
+            SourceKind::IpyNotebook(_) => PySourceType::Ipynb,
+        }
+    }
+}
+
 #[derive(Debug, Clone, PartialEq)]
 pub struct Source {
     kind: SourceKind,

crates/red_knot/src/symbols.rs

@@ -1,956 +0,0 @@
-#![allow(dead_code)]
-
-use std::hash::{Hash, Hasher};
-use std::iter::{Copied, DoubleEndedIterator, FusedIterator};
-use std::num::NonZeroU32;
-use std::ops::{Deref, DerefMut};
-use std::sync::Arc;
-
-use bitflags::bitflags;
-use hashbrown::hash_map::{Keys, RawEntryMut};
-use rustc_hash::{FxHashMap, FxHasher};
-
-use ruff_index::{newtype_index, IndexVec};
-use ruff_python_ast as ast;
-use ruff_python_ast::visitor::preorder::PreorderVisitor;
-
-use crate::ast_ids::TypedNodeKey;
-use crate::cache::KeyValueCache;
-use crate::db::{HasJar, QueryResult, SemanticDb, SemanticJar};
-use crate::files::FileId;
-use crate::module::ModuleName;
-use crate::Name;
-
-#[allow(unreachable_pub)]
-#[tracing::instrument(level = "debug", skip(db))]
-pub fn symbol_table<Db>(db: &Db, file_id: FileId) -> QueryResult<Arc<SymbolTable>>
-where
-    Db: SemanticDb + HasJar<SemanticJar>,
-{
-    let jar = db.jar()?;
-
-    jar.symbol_tables.get(&file_id, |_| {
-        let parsed = db.parse(file_id)?;
-        Ok(Arc::from(SymbolTable::from_ast(parsed.ast())))
-    })
-}
-
-type Map<K, V> = hashbrown::HashMap<K, V, ()>;
-
-#[newtype_index]
-pub(crate) struct ScopeId;
-
-impl ScopeId {
-    pub(crate) fn scope(self, table: &SymbolTable) -> &Scope {
-        &table.scopes_by_id[self]
-    }
-}
-
-#[newtype_index]
-pub struct SymbolId;
-
-impl SymbolId {
-    pub(crate) fn symbol(self, table: &SymbolTable) -> &Symbol {
-        &table.symbols_by_id[self]
-    }
-}
-
-#[derive(Copy, Clone, Debug, PartialEq)]
-pub(crate) enum ScopeKind {
-    Module,
-    Annotation,
-    Class,
-    Function,
-}
-
-#[derive(Debug)]
-pub(crate) struct Scope {
-    name: Name,
-    kind: ScopeKind,
-    child_scopes: Vec<ScopeId>,
-    /// symbol IDs, hashed by symbol name
-    symbols_by_name: Map<SymbolId, ()>,
-}
-
-impl Scope {
-    pub(crate) fn name(&self) -> &str {
-        self.name.as_str()
-    }
-
-    pub(crate) fn kind(&self) -> ScopeKind {
-        self.kind
-    }
-}
-
-#[derive(Debug)]
-pub(crate) enum Kind {
-    FreeVar,
-    CellVar,
-    CellVarAssigned,
-    ExplicitGlobal,
-    ImplicitGlobal,
-}
-
-bitflags! {
-    #[derive(Copy,Clone,Debug)]
-    pub(crate) struct SymbolFlags: u8 {
-        const IS_USED         = 1 << 0;
-        const IS_DEFINED      = 1 << 1;
-        /// TODO: This flag is not yet set by anything
-        const MARKED_GLOBAL   = 1 << 2;
-        /// TODO: This flag is not yet set by anything
-        const MARKED_NONLOCAL = 1 << 3;
-    }
-}
-
-#[derive(Debug)]
-pub(crate) struct Symbol {
-    name: Name,
-    flags: SymbolFlags,
-    scope_id: ScopeId,
-    // kind: Kind,
-}
-
-impl Symbol {
-    pub(crate) fn name(&self) -> &str {
-        self.name.as_str()
-    }
-
-    /// Is the symbol used in its containing scope?
-    pub(crate) fn is_used(&self) -> bool {
-        self.flags.contains(SymbolFlags::IS_USED)
-    }
-
-    /// Is the symbol defined in its containing scope?
-    pub(crate) fn is_defined(&self) -> bool {
-        self.flags.contains(SymbolFlags::IS_DEFINED)
-    }
-
-    // TODO: implement Symbol.kind 2-pass analysis to categorize as: free-var, cell-var,
-    // explicit-global, implicit-global and implement Symbol.kind by modifying the preorder
-    // traversal code
-}
-
-// TODO storing TypedNodeKey for definitions means we have to search to find them again in the AST;
-// this is at best O(log n). If looking up definitions is a bottleneck we should look for
-// alternatives here.
-#[derive(Clone, Debug)]
-pub(crate) enum Definition {
-    // For the import cases, we don't need reference to any arbitrary AST subtrees (annotations,
-    // RHS), and referencing just the import statement node is imprecise (a single import statement
-    // can assign many symbols, we'd have to re-search for the one we care about), so we just copy
-    // the small amount of information we need from the AST.
-    Import(ImportDefinition),
-    ImportFrom(ImportFromDefinition),
-    ClassDef(ClassDefinition),
-    FunctionDef(TypedNodeKey<ast::StmtFunctionDef>),
-    Assignment(TypedNodeKey<ast::StmtAssign>),
-    AnnotatedAssignment(TypedNodeKey<ast::StmtAnnAssign>),
-    // TODO with statements, except handlers, function args...
-}
-
-#[derive(Clone, Debug)]
-pub(crate) struct ImportDefinition {
-    pub(crate) module: ModuleName,
-}
-
-#[derive(Clone, Debug)]
-pub(crate) struct ImportFromDefinition {
-    pub(crate) module: Option<ModuleName>,
-    pub(crate) name: Name,
-    pub(crate) level: u32,
-}
-
-impl ImportFromDefinition {
-    pub(crate) fn module(&self) -> Option<&ModuleName> {
-        self.module.as_ref()
-    }
-
-    pub(crate) fn name(&self) -> &Name {
-        &self.name
-    }
-
-    pub(crate) fn level(&self) -> u32 {
-        self.level
-    }
-}
-
-#[derive(Clone, Debug)]
-pub(crate) struct ClassDefinition {
-    pub(crate) node_key: TypedNodeKey<ast::StmtClassDef>,
-    pub(crate) scope_id: ScopeId,
-}
-
-#[derive(Debug, Clone)]
-pub enum Dependency {
-    Module(ModuleName),
-    Relative {
-        level: NonZeroU32,
-        module: Option<ModuleName>,
-    },
-}
-
-/// Table of all symbols in all scopes for a module.
-#[derive(Debug)]
-pub struct SymbolTable {
-    scopes_by_id: IndexVec<ScopeId, Scope>,
-    symbols_by_id: IndexVec<SymbolId, Symbol>,
-    defs: FxHashMap<SymbolId, Vec<Definition>>,
-    dependencies: Vec<Dependency>,
-}
-
-impl SymbolTable {
-    pub(crate) fn from_ast(module: &ast::ModModule) -> Self {
-        let root_scope_id = SymbolTable::root_scope_id();
-        let mut builder = SymbolTableBuilder {
-            table: SymbolTable::new(),
-            scopes: vec![root_scope_id],
-            current_definition: None,
-        };
-        builder.visit_body(&module.body);
-        builder.table
-    }
-
-    pub(crate) fn new() -> Self {
-        let mut table = SymbolTable {
-            scopes_by_id: IndexVec::new(),
-            symbols_by_id: IndexVec::new(),
-            defs: FxHashMap::default(),
-            dependencies: Vec::new(),
-        };
-        table.scopes_by_id.push(Scope {
-            name: Name::new("<module>"),
-            kind: ScopeKind::Module,
-            child_scopes: Vec::new(),
-            symbols_by_name: Map::default(),
-        });
-        table
-    }
-
-    pub(crate) fn dependencies(&self) -> &[Dependency] {
-        &self.dependencies
-    }
-
-    pub(crate) const fn root_scope_id() -> ScopeId {
-        ScopeId::from_usize(0)
-    }
-
-    pub(crate) fn root_scope(&self) -> &Scope {
-        &self.scopes_by_id[SymbolTable::root_scope_id()]
-    }
-
-    pub(crate) fn symbol_ids_for_scope(&self, scope_id: ScopeId) -> Copied<Keys<SymbolId, ()>> {
-        self.scopes_by_id[scope_id].symbols_by_name.keys().copied()
-    }
-
-    pub(crate) fn symbols_for_scope(
-        &self,
-        scope_id: ScopeId,
-    ) -> SymbolIterator<Copied<Keys<SymbolId, ()>>> {
-        SymbolIterator {
-            table: self,
-            ids: self.symbol_ids_for_scope(scope_id),
-        }
-    }
-
-    pub(crate) fn root_symbol_ids(&self) -> Copied<Keys<SymbolId, ()>> {
-        self.symbol_ids_for_scope(SymbolTable::root_scope_id())
-    }
-
-    pub(crate) fn root_symbols(&self) -> SymbolIterator<Copied<Keys<SymbolId, ()>>> {
-        self.symbols_for_scope(SymbolTable::root_scope_id())
-    }
-
-    pub(crate) fn child_scope_ids_of(&self, scope_id: ScopeId) -> &[ScopeId] {
-        &self.scopes_by_id[scope_id].child_scopes
-    }
-
-    pub(crate) fn child_scopes_of(&self, scope_id: ScopeId) -> ScopeIterator<&[ScopeId]> {
-        ScopeIterator {
-            table: self,
-            ids: self.child_scope_ids_of(scope_id),
-        }
-    }
-
-    pub(crate) fn root_child_scope_ids(&self) -> &[ScopeId] {
-        self.child_scope_ids_of(SymbolTable::root_scope_id())
-    }
-
-    pub(crate) fn root_child_scopes(&self) -> ScopeIterator<&[ScopeId]> {
-        self.child_scopes_of(SymbolTable::root_scope_id())
-    }
-
-    pub(crate) fn symbol_id_by_name(&self, scope_id: ScopeId, name: &str) -> Option<SymbolId> {
-        let scope = &self.scopes_by_id[scope_id];
-        let hash = SymbolTable::hash_name(name);
-        let name = Name::new(name);
-        scope
-            .symbols_by_name
-            .raw_entry()
-            .from_hash(hash, |symid| self.symbols_by_id[*symid].name == name)
-            .map(|(symbol_id, ())| *symbol_id)
-    }
-
-    pub(crate) fn symbol_by_name(&self, scope_id: ScopeId, name: &str) -> Option<&Symbol> {
-        Some(&self.symbols_by_id[self.symbol_id_by_name(scope_id, name)?])
-    }
-
-    pub(crate) fn root_symbol_id_by_name(&self, name: &str) -> Option<SymbolId> {
-        self.symbol_id_by_name(SymbolTable::root_scope_id(), name)
-    }
-
-    pub(crate) fn root_symbol_by_name(&self, name: &str) -> Option<&Symbol> {
-        self.symbol_by_name(SymbolTable::root_scope_id(), name)
-    }
-
-    pub(crate) fn definitions(&self, symbol_id: SymbolId) -> &[Definition] {
-        self.defs
-            .get(&symbol_id)
-            .map(std::vec::Vec::as_slice)
-            .unwrap_or_default()
-    }
-
-    pub(crate) fn all_definitions(&self) -> impl Iterator<Item = (SymbolId, &Definition)> + '_ {
-        self.defs
-            .iter()
-            .flat_map(|(sym_id, defs)| defs.iter().map(move |def| (*sym_id, def)))
-    }
-
-    fn add_or_update_symbol(
-        &mut self,
-        scope_id: ScopeId,
-        name: &str,
-        flags: SymbolFlags,
-    ) -> SymbolId {
-        let hash = SymbolTable::hash_name(name);
-        let scope = &mut self.scopes_by_id[scope_id];
-        let name = Name::new(name);
-
-        let entry = scope
-            .symbols_by_name
-            .raw_entry_mut()
-            .from_hash(hash, |existing| self.symbols_by_id[*existing].name == name);
-
-        match entry {
-            RawEntryMut::Occupied(entry) => {
-                if let Some(symbol) = self.symbols_by_id.get_mut(*entry.key()) {
-                    symbol.flags.insert(flags);
-                };
-                *entry.key()
-            }
-            RawEntryMut::Vacant(entry) => {
-                let id = self.symbols_by_id.push(Symbol {
-                    name,
-                    flags,
-                    scope_id,
-                });
-                entry.insert_with_hasher(hash, id, (), |_| hash);
-                id
-            }
-        }
-    }
-
-    fn add_child_scope(
-        &mut self,
-        parent_scope_id: ScopeId,
-        name: &str,
-        kind: ScopeKind,
-    ) -> ScopeId {
-        let new_scope_id = self.scopes_by_id.push(Scope {
-            name: Name::new(name),
-            kind,
-            child_scopes: Vec::new(),
-            symbols_by_name: Map::default(),
-        });
-        let parent_scope = &mut self.scopes_by_id[parent_scope_id];
-        parent_scope.child_scopes.push(new_scope_id);
-        new_scope_id
-    }
-
-    fn hash_name(name: &str) -> u64 {
-        let mut hasher = FxHasher::default();
-        name.hash(&mut hasher);
-        hasher.finish()
-    }
-}
-
-pub(crate) struct SymbolIterator<'a, I> {
-    table: &'a SymbolTable,
-    ids: I,
-}
-
-impl<'a, I> Iterator for SymbolIterator<'a, I>
-where
-    I: Iterator<Item = SymbolId>,
-{
-    type Item = &'a Symbol;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        let id = self.ids.next()?;
-        Some(&self.table.symbols_by_id[id])
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        self.ids.size_hint()
-    }
-}
-
-impl<'a, I> FusedIterator for SymbolIterator<'a, I> where
-    I: Iterator<Item = SymbolId> + FusedIterator
-{
-}
-
-impl<'a, I> DoubleEndedIterator for SymbolIterator<'a, I>
-where
-    I: Iterator<Item = SymbolId> + DoubleEndedIterator,
-{
-    fn next_back(&mut self) -> Option<Self::Item> {
-        let id = self.ids.next_back()?;
-        Some(&self.table.symbols_by_id[id])
-    }
-}
-
-pub(crate) struct ScopeIterator<'a, I> {
-    table: &'a SymbolTable,
-    ids: I,
-}
-
-impl<'a, I> Iterator for ScopeIterator<'a, I>
-where
-    I: Iterator<Item = ScopeId>,
-{
-    type Item = &'a Scope;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        let id = self.ids.next()?;
-        Some(&self.table.scopes_by_id[id])
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        self.ids.size_hint()
-    }
-}
-
-impl<'a, I> FusedIterator for ScopeIterator<'a, I> where I: Iterator<Item = ScopeId> + FusedIterator {}
-
-impl<'a, I> DoubleEndedIterator for ScopeIterator<'a, I>
-where
-    I: Iterator<Item = ScopeId> + DoubleEndedIterator,
-{
-    fn next_back(&mut self) -> Option<Self::Item> {
-        let id = self.ids.next_back()?;
-        Some(&self.table.scopes_by_id[id])
-    }
-}
-
-struct SymbolTableBuilder {
-    table: SymbolTable,
-    scopes: Vec<ScopeId>,
-    /// the definition whose target(s) we are currently walking
-    current_definition: Option<Definition>,
-}
-
-impl SymbolTableBuilder {
-    fn add_or_update_symbol(&mut self, identifier: &str, flags: SymbolFlags) -> SymbolId {
-        self.table
-            .add_or_update_symbol(self.cur_scope(), identifier, flags)
-    }
-
-    fn add_or_update_symbol_with_def(
-        &mut self,
-        identifier: &str,
-        definition: Definition,
-    ) -> SymbolId {
-        let symbol_id = self.add_or_update_symbol(identifier, SymbolFlags::IS_DEFINED);
-        self.table
-            .defs
-            .entry(symbol_id)
-            .or_default()
-            .push(definition);
-        symbol_id
-    }
-
-    fn push_scope(&mut self, name: &str, kind: ScopeKind) -> ScopeId {
-        let scope_id = self.table.add_child_scope(self.cur_scope(), name, kind);
-        self.scopes.push(scope_id);
-        scope_id
-    }
-
-    fn pop_scope(&mut self) -> ScopeId {
-        self.scopes
-            .pop()
-            .expect("Scope stack should never be empty")
-    }
-
-    fn cur_scope(&self) -> ScopeId {
-        *self
-            .scopes
-            .last()
-            .expect("Scope stack should never be empty")
-    }
-
-    fn with_type_params(
-        &mut self,
-        name: &str,
-        params: &Option<Box<ast::TypeParams>>,
-        nested: impl FnOnce(&mut Self) -> ScopeId,
-    ) -> ScopeId {
-        if let Some(type_params) = params {
-            self.push_scope(name, ScopeKind::Annotation);
-            for type_param in &type_params.type_params {
-                let name = match type_param {
-                    ast::TypeParam::TypeVar(ast::TypeParamTypeVar { name, .. }) => name,
-                    ast::TypeParam::ParamSpec(ast::TypeParamParamSpec { name, .. }) => name,
-                    ast::TypeParam::TypeVarTuple(ast::TypeParamTypeVarTuple { name, .. }) => name,
-                };
-                self.add_or_update_symbol(name, SymbolFlags::IS_DEFINED);
-            }
-        }
-        let scope_id = nested(self);
-        if params.is_some() {
-            self.pop_scope();
-        }
-        scope_id
-    }
-}
-
-impl PreorderVisitor<'_> for SymbolTableBuilder {
-    fn visit_expr(&mut self, expr: &ast::Expr) {
-        if let ast::Expr::Name(ast::ExprName { id, ctx, .. }) = expr {
-            let flags = match ctx {
-                ast::ExprContext::Load => SymbolFlags::IS_USED,
-                ast::ExprContext::Store => SymbolFlags::IS_DEFINED,
-                ast::ExprContext::Del => SymbolFlags::IS_DEFINED,
-                ast::ExprContext::Invalid => SymbolFlags::empty(),
-            };
-            self.add_or_update_symbol(id, flags);
-            if flags.contains(SymbolFlags::IS_DEFINED) {
-                if let Some(curdef) = self.current_definition.clone() {
-                    self.add_or_update_symbol_with_def(id, curdef);
-                }
-            }
-        }
-        ast::visitor::preorder::walk_expr(self, expr);
-    }
-
-    fn visit_stmt(&mut self, stmt: &ast::Stmt) {
-        // TODO need to capture more definition statements here
-        match stmt {
-            ast::Stmt::ClassDef(node) => {
-                let scope_id = self.with_type_params(&node.name, &node.type_params, |builder| {
-                    let scope_id = builder.push_scope(&node.name, ScopeKind::Class);
-                    ast::visitor::preorder::walk_stmt(builder, stmt);
-                    builder.pop_scope();
-                    scope_id
-                });
-                let def = Definition::ClassDef(ClassDefinition {
-                    node_key: TypedNodeKey::from_node(node),
-                    scope_id,
-                });
-                self.add_or_update_symbol_with_def(&node.name, def);
-            }
-            ast::Stmt::FunctionDef(node) => {
-                let def = Definition::FunctionDef(TypedNodeKey::from_node(node));
-                self.add_or_update_symbol_with_def(&node.name, def);
-                self.with_type_params(&node.name, &node.type_params, |builder| {
-                    let scope_id = builder.push_scope(&node.name, ScopeKind::Function);
-                    ast::visitor::preorder::walk_stmt(builder, stmt);
-                    builder.pop_scope();
-                    scope_id
-                });
-            }
-            ast::Stmt::Import(ast::StmtImport { names, .. }) => {
-                for alias in names {
-                    let symbol_name = if let Some(asname) = &alias.asname {
-                        asname.id.as_str()
-                    } else {
-                        alias.name.id.split('.').next().unwrap()
-                    };
-
-                    let module = ModuleName::new(&alias.name.id);
-
-                    let def = Definition::Import(ImportDefinition {
-                        module: module.clone(),
-                    });
-                    self.add_or_update_symbol_with_def(symbol_name, def);
-                    self.table.dependencies.push(Dependency::Module(module));
-                }
-            }
-            ast::Stmt::ImportFrom(ast::StmtImportFrom {
-                module,
-                names,
-                level,
-                ..
-            }) => {
-                let module = module.as_ref().map(|m| ModuleName::new(&m.id));
-
-                for alias in names {
-                    let symbol_name = if let Some(asname) = &alias.asname {
-                        asname.id.as_str()
-                    } else {
-                        alias.name.id.as_str()
-                    };
-                    let def = Definition::ImportFrom(ImportFromDefinition {
-                        module: module.clone(),
-                        name: Name::new(&alias.name.id),
-                        level: *level,
-                    });
-                    self.add_or_update_symbol_with_def(symbol_name, def);
-                }
-
-                let dependency = if let Some(module) = module {
-                    match NonZeroU32::new(*level) {
-                        Some(level) => Dependency::Relative {
-                            level,
-                            module: Some(module),
-                        },
-                        None => Dependency::Module(module),
-                    }
-                } else {
-                    Dependency::Relative {
-                        level: NonZeroU32::new(*level)
-                            .expect("Import without a module to have a level > 0"),
-                        module,
-                    }
-                };
-
-                self.table.dependencies.push(dependency);
-            }
-            ast::Stmt::Assign(node) => {
-                debug_assert!(self.current_definition.is_none());
-                self.current_definition =
-                    Some(Definition::Assignment(TypedNodeKey::from_node(node)));
-                ast::visitor::preorder::walk_stmt(self, stmt);
-                self.current_definition = None;
-            }
-            _ => {
-                ast::visitor::preorder::walk_stmt(self, stmt);
-            }
-        }
-    }
-}
-
-#[derive(Debug, Default)]
-pub struct SymbolTablesStorage(KeyValueCache<FileId, Arc<SymbolTable>>);
-
-impl Deref for SymbolTablesStorage {
-    type Target = KeyValueCache<FileId, Arc<SymbolTable>>;
-
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-impl DerefMut for SymbolTablesStorage {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.0
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use textwrap::dedent;
-
-    use crate::parse::Parsed;
-    use crate::symbols::ScopeKind;
-
-    use super::{SymbolFlags, SymbolId, SymbolIterator, SymbolTable};
-
-    mod from_ast {
-        use super::*;
-
-        fn parse(code: &str) -> Parsed {
-            Parsed::from_text(&dedent(code))
-        }
-
-        fn names<I>(it: SymbolIterator<I>) -> Vec<&str>
-        where
-            I: Iterator<Item = SymbolId>,
-        {
-            let mut symbols: Vec<_> = it.map(|sym| sym.name.as_str()).collect();
-            symbols.sort_unstable();
-            symbols
-        }
-
-        #[test]
-        fn empty() {
-            let parsed = parse("");
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()).len(), 0);
-        }
-
-        #[test]
-        fn simple() {
-            let parsed = parse("x");
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["x"]);
-            assert_eq!(
-                table
-                    .definitions(table.root_symbol_id_by_name("x").unwrap())
-                    .len(),
-                0
-            );
-        }
-
-        #[test]
-        fn annotation_only() {
-            let parsed = parse("x: int");
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["int", "x"]);
-            // TODO record definition
-        }
-
-        #[test]
-        fn import() {
-            let parsed = parse("import foo");
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["foo"]);
-            assert_eq!(
-                table
-                    .definitions(table.root_symbol_id_by_name("foo").unwrap())
-                    .len(),
-                1
-            );
-        }
-
-        #[test]
-        fn import_sub() {
-            let parsed = parse("import foo.bar");
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["foo"]);
-        }
-
-        #[test]
-        fn import_as() {
-            let parsed = parse("import foo.bar as baz");
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["baz"]);
-        }
-
-        #[test]
-        fn import_from() {
-            let parsed = parse("from bar import foo");
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["foo"]);
-            assert_eq!(
-                table
-                    .definitions(table.root_symbol_id_by_name("foo").unwrap())
-                    .len(),
-                1
-            );
-            assert!(
-                table.root_symbol_id_by_name("foo").is_some_and(|sid| {
-                    let s = sid.symbol(&table);
-                    s.is_defined() || !s.is_used()
-                }),
-                "symbols that are defined get the defined flag"
-            );
-        }
-
-        #[test]
-        fn assign() {
-            let parsed = parse("x = foo");
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["foo", "x"]);
-            assert_eq!(
-                table
-                    .definitions(table.root_symbol_id_by_name("x").unwrap())
-                    .len(),
-                1
-            );
-            assert!(
-                table.root_symbol_id_by_name("foo").is_some_and(|sid| {
-                    let s = sid.symbol(&table);
-                    !s.is_defined() && s.is_used()
-                }),
-                "a symbol used but not defined in a scope should have only the used flag"
-            );
-        }
-
-        #[test]
-        fn class_scope() {
-            let parsed = parse(
-                "
-                class C:
-                    x = 1
-                y = 2
-                ",
-            );
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["C", "y"]);
-            let scopes = table.root_child_scope_ids();
-            assert_eq!(scopes.len(), 1);
-            let c_scope = scopes[0].scope(&table);
-            assert_eq!(c_scope.kind(), ScopeKind::Class);
-            assert_eq!(c_scope.name(), "C");
-            assert_eq!(names(table.symbols_for_scope(scopes[0])), vec!["x"]);
-            assert_eq!(
-                table
-                    .definitions(table.root_symbol_id_by_name("C").unwrap())
-                    .len(),
-                1
-            );
-        }
-
-        #[test]
-        fn func_scope() {
-            let parsed = parse(
-                "
-                def func():
-                    x = 1
-                y = 2
-                ",
-            );
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["func", "y"]);
-            let scopes = table.root_child_scope_ids();
-            assert_eq!(scopes.len(), 1);
-            let func_scope = scopes[0].scope(&table);
-            assert_eq!(func_scope.kind(), ScopeKind::Function);
-            assert_eq!(func_scope.name(), "func");
-            assert_eq!(names(table.symbols_for_scope(scopes[0])), vec!["x"]);
-            assert_eq!(
-                table
-                    .definitions(table.root_symbol_id_by_name("func").unwrap())
-                    .len(),
-                1
-            );
-        }
-
-        #[test]
-        fn dupes() {
-            let parsed = parse(
-                "
-                def func():
-                    x = 1
-                def func():
-                    y = 2
-                ",
-            );
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["func"]);
-            let scopes = table.root_child_scope_ids();
-            assert_eq!(scopes.len(), 2);
-            let func_scope_1 = scopes[0].scope(&table);
-            let func_scope_2 = scopes[1].scope(&table);
-            assert_eq!(func_scope_1.kind(), ScopeKind::Function);
-            assert_eq!(func_scope_1.name(), "func");
-            assert_eq!(func_scope_2.kind(), ScopeKind::Function);
-            assert_eq!(func_scope_2.name(), "func");
-            assert_eq!(names(table.symbols_for_scope(scopes[0])), vec!["x"]);
-            assert_eq!(names(table.symbols_for_scope(scopes[1])), vec!["y"]);
-            assert_eq!(
-                table
-                    .definitions(table.root_symbol_id_by_name("func").unwrap())
-                    .len(),
-                2
-            );
-        }
-
-        #[test]
-        fn generic_func() {
-            let parsed = parse(
-                "
-                def func[T]():
-                    x = 1
-                ",
-            );
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["func"]);
-            let scopes = table.root_child_scope_ids();
-            assert_eq!(scopes.len(), 1);
-            let ann_scope_id = scopes[0];
-            let ann_scope = ann_scope_id.scope(&table);
-            assert_eq!(ann_scope.kind(), ScopeKind::Annotation);
-            assert_eq!(ann_scope.name(), "func");
-            assert_eq!(names(table.symbols_for_scope(ann_scope_id)), vec!["T"]);
-            let scopes = table.child_scope_ids_of(ann_scope_id);
-            assert_eq!(scopes.len(), 1);
-            let func_scope_id = scopes[0];
-            let func_scope = func_scope_id.scope(&table);
-            assert_eq!(func_scope.kind(), ScopeKind::Function);
-            assert_eq!(func_scope.name(), "func");
-            assert_eq!(names(table.symbols_for_scope(func_scope_id)), vec!["x"]);
-        }
-
-        #[test]
-        fn generic_class() {
-            let parsed = parse(
-                "
-                class C[T]:
-                    x = 1
-                ",
-            );
-            let table = SymbolTable::from_ast(parsed.ast());
-            assert_eq!(names(table.root_symbols()), vec!["C"]);
-            let scopes = table.root_child_scope_ids();
-            assert_eq!(scopes.len(), 1);
-            let ann_scope_id = scopes[0];
-            let ann_scope = ann_scope_id.scope(&table);
-            assert_eq!(ann_scope.kind(), ScopeKind::Annotation);
-            assert_eq!(ann_scope.name(), "C");
-            assert_eq!(names(table.symbols_for_scope(ann_scope_id)), vec!["T"]);
-            assert!(
-                table
-                    .symbol_by_name(ann_scope_id, "T")
-                    .is_some_and(|s| s.is_defined() && !s.is_used()),
-                "type parameters are defined by the scope that introduces them"
-            );
-            let scopes = table.child_scope_ids_of(ann_scope_id);
-            assert_eq!(scopes.len(), 1);
-            let func_scope_id = scopes[0];
-            let func_scope = func_scope_id.scope(&table);
-            assert_eq!(func_scope.kind(), ScopeKind::Class);
-            assert_eq!(func_scope.name(), "C");
-            assert_eq!(names(table.symbols_for_scope(func_scope_id)), vec!["x"]);
-        }
-    }
-
-    #[test]
-    fn insert_same_name_symbol_twice() {
-        let mut table = SymbolTable::new();
-        let root_scope_id = SymbolTable::root_scope_id();
-        let symbol_id_1 = table.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::IS_DEFINED);
-        let symbol_id_2 = table.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::IS_USED);
-        assert_eq!(symbol_id_1, symbol_id_2);
-        assert!(symbol_id_1.symbol(&table).is_used(), "flags must merge");
-        assert!(symbol_id_1.symbol(&table).is_defined(), "flags must merge");
-    }
-
-    #[test]
-    fn insert_different_named_symbols() {
-        let mut table = SymbolTable::new();
-        let root_scope_id = SymbolTable::root_scope_id();
-        let symbol_id_1 = table.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::empty());
-        let symbol_id_2 = table.add_or_update_symbol(root_scope_id, "bar", SymbolFlags::empty());
-        assert_ne!(symbol_id_1, symbol_id_2);
-    }
-
-    #[test]
-    fn add_child_scope_with_symbol() {
-        let mut table = SymbolTable::new();
-        let root_scope_id = SymbolTable::root_scope_id();
-        let foo_symbol_top = table.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::empty());
-        let c_scope = table.add_child_scope(root_scope_id, "C", ScopeKind::Class);
-        let foo_symbol_inner = table.add_or_update_symbol(c_scope, "foo", SymbolFlags::empty());
-        assert_ne!(foo_symbol_top, foo_symbol_inner);
-    }
-
-    #[test]
-    fn scope_from_id() {
-        let table = SymbolTable::new();
-        let root_scope_id = SymbolTable::root_scope_id();
-        let scope = root_scope_id.scope(&table);
-        assert_eq!(scope.name.as_str(), "<module>");
-        assert_eq!(scope.kind, ScopeKind::Module);
-    }
-
-    #[test]
-    fn symbol_from_id() {
-        let mut table = SymbolTable::new();
-        let root_scope_id = SymbolTable::root_scope_id();
-        let foo_symbol_id = table.add_or_update_symbol(root_scope_id, "foo", SymbolFlags::empty());
-        let symbol = foo_symbol_id.symbol(&table);
-        assert_eq!(symbol.name.as_str(), "foo");
-    }
-}

crates/red_knot/src/types.rs

@@ -1,600 +0,0 @@
-#![allow(dead_code)]
-use crate::ast_ids::NodeKey;
-use crate::db::{HasJar, QueryResult, SemanticDb, SemanticJar};
-use crate::files::FileId;
-use crate::symbols::{ScopeId, SymbolId};
-use crate::{FxDashMap, FxIndexSet, Name};
-use ruff_index::{newtype_index, IndexVec};
-use rustc_hash::FxHashMap;
-
-pub(crate) mod infer;
-
-pub(crate) use infer::infer_symbol_type;
-
-/// unique ID for a type
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
-pub enum Type {
-    /// the dynamic or gradual type: a statically-unknown set of values
-    Any,
-    /// the empty set of values
-    Never,
-    /// unknown type (no annotation)
-    /// equivalent to Any, or to object in strict mode
-    Unknown,
-    /// name is not bound to any value
-    Unbound,
-    /// a specific function object
-    Function(FunctionTypeId),
-    /// a specific class object
-    Class(ClassTypeId),
-    /// the set of Python objects with the given class in their __class__'s method resolution order
-    Instance(ClassTypeId),
-    Union(UnionTypeId),
-    Intersection(IntersectionTypeId),
-    // TODO protocols, callable types, overloads, generics, type vars
-}
-
-impl Type {
-    fn display<'a>(&'a self, store: &'a TypeStore) -> DisplayType<'a> {
-        DisplayType { ty: self, store }
-    }
-
-    pub const fn is_unbound(&self) -> bool {
-        matches!(self, Type::Unbound)
-    }
-
-    pub const fn is_unknown(&self) -> bool {
-        matches!(self, Type::Unknown)
-    }
-}
-
-impl From<FunctionTypeId> for Type {
-    fn from(id: FunctionTypeId) -> Self {
-        Type::Function(id)
-    }
-}
-
-impl From<UnionTypeId> for Type {
-    fn from(id: UnionTypeId) -> Self {
-        Type::Union(id)
-    }
-}
-
-impl From<IntersectionTypeId> for Type {
-    fn from(id: IntersectionTypeId) -> Self {
-        Type::Intersection(id)
-    }
-}
-
-// TODO: currently calling `get_function` et al and holding on to the `FunctionTypeRef` will lock a
-// shard of this dashmap, for as long as you hold the reference. This may be a problem. We could
-// switch to having all the arenas hold Arc, or we could see if we can split up ModuleTypeStore,
-// and/or give it inner mutability and finer-grained internal locking.
-#[derive(Debug, Default)]
-pub struct TypeStore {
-    modules: FxDashMap<FileId, ModuleTypeStore>,
-}
-
-impl TypeStore {
-    pub fn remove_module(&mut self, file_id: FileId) {
-        self.modules.remove(&file_id);
-    }
-
-    pub fn cache_symbol_type(&self, file_id: FileId, symbol_id: SymbolId, ty: Type) {
-        self.add_or_get_module(file_id)
-            .symbol_types
-            .insert(symbol_id, ty);
-    }
-
-    pub fn cache_node_type(&self, file_id: FileId, node_key: NodeKey, ty: Type) {
-        self.add_or_get_module(file_id)
-            .node_types
-            .insert(node_key, ty);
-    }
-
-    pub fn get_cached_symbol_type(&self, file_id: FileId, symbol_id: SymbolId) -> Option<Type> {
-        self.try_get_module(file_id)?
-            .symbol_types
-            .get(&symbol_id)
-            .copied()
-    }
-
-    pub fn get_cached_node_type(&self, file_id: FileId, node_key: &NodeKey) -> Option<Type> {
-        self.try_get_module(file_id)?
-            .node_types
-            .get(node_key)
-            .copied()
-    }
-
-    fn add_or_get_module(&self, file_id: FileId) -> ModuleStoreRefMut {
-        self.modules
-            .entry(file_id)
-            .or_insert_with(|| ModuleTypeStore::new(file_id))
-    }
-
-    fn get_module(&self, file_id: FileId) -> ModuleStoreRef {
-        self.try_get_module(file_id).expect("module should exist")
-    }
-
-    fn try_get_module(&self, file_id: FileId) -> Option<ModuleStoreRef> {
-        self.modules.get(&file_id)
-    }
-
-    fn add_function(&self, file_id: FileId, name: &str, decorators: Vec<Type>) -> FunctionTypeId {
-        self.add_or_get_module(file_id)
-            .add_function(name, decorators)
-    }
-
-    fn add_class(
-        &self,
-        file_id: FileId,
-        name: &str,
-        scope_id: ScopeId,
-        bases: Vec<Type>,
-    ) -> ClassTypeId {
-        self.add_or_get_module(file_id)
-            .add_class(name, scope_id, bases)
-    }
-
-    fn add_union(&mut self, file_id: FileId, elems: &[Type]) -> UnionTypeId {
-        self.add_or_get_module(file_id).add_union(elems)
-    }
-
-    fn add_intersection(
-        &mut self,
-        file_id: FileId,
-        positive: &[Type],
-        negative: &[Type],
-    ) -> IntersectionTypeId {
-        self.add_or_get_module(file_id)
-            .add_intersection(positive, negative)
-    }
-
-    fn get_function(&self, id: FunctionTypeId) -> FunctionTypeRef {
-        FunctionTypeRef {
-            module_store: self.get_module(id.file_id),
-            function_id: id.func_id,
-        }
-    }
-
-    fn get_class(&self, id: ClassTypeId) -> ClassTypeRef {
-        ClassTypeRef {
-            module_store: self.get_module(id.file_id),
-            class_id: id.class_id,
-        }
-    }
-
-    fn get_union(&self, id: UnionTypeId) -> UnionTypeRef {
-        UnionTypeRef {
-            module_store: self.get_module(id.file_id),
-            union_id: id.union_id,
-        }
-    }
-
-    fn get_intersection(&self, id: IntersectionTypeId) -> IntersectionTypeRef {
-        IntersectionTypeRef {
-            module_store: self.get_module(id.file_id),
-            intersection_id: id.intersection_id,
-        }
-    }
-}
-
-type ModuleStoreRef<'a> = dashmap::mapref::one::Ref<
-    'a,
-    FileId,
-    ModuleTypeStore,
-    std::hash::BuildHasherDefault<rustc_hash::FxHasher>,
->;
-
-type ModuleStoreRefMut<'a> = dashmap::mapref::one::RefMut<
-    'a,
-    FileId,
-    ModuleTypeStore,
-    std::hash::BuildHasherDefault<rustc_hash::FxHasher>,
->;
-
-#[derive(Debug)]
-pub(crate) struct FunctionTypeRef<'a> {
-    module_store: ModuleStoreRef<'a>,
-    function_id: ModuleFunctionTypeId,
-}
-
-impl<'a> std::ops::Deref for FunctionTypeRef<'a> {
-    type Target = FunctionType;
-
-    fn deref(&self) -> &Self::Target {
-        self.module_store.get_function(self.function_id)
-    }
-}
-
-#[derive(Debug)]
-pub(crate) struct ClassTypeRef<'a> {
-    module_store: ModuleStoreRef<'a>,
-    class_id: ModuleClassTypeId,
-}
-
-impl<'a> std::ops::Deref for ClassTypeRef<'a> {
-    type Target = ClassType;
-
-    fn deref(&self) -> &Self::Target {
-        self.module_store.get_class(self.class_id)
-    }
-}
-
-#[derive(Debug)]
-pub(crate) struct UnionTypeRef<'a> {
-    module_store: ModuleStoreRef<'a>,
-    union_id: ModuleUnionTypeId,
-}
-
-impl<'a> std::ops::Deref for UnionTypeRef<'a> {
-    type Target = UnionType;
-
-    fn deref(&self) -> &Self::Target {
-        self.module_store.get_union(self.union_id)
-    }
-}
-
-#[derive(Debug)]
-pub(crate) struct IntersectionTypeRef<'a> {
-    module_store: ModuleStoreRef<'a>,
-    intersection_id: ModuleIntersectionTypeId,
-}
-
-impl<'a> std::ops::Deref for IntersectionTypeRef<'a> {
-    type Target = IntersectionType;
-
-    fn deref(&self) -> &Self::Target {
-        self.module_store.get_intersection(self.intersection_id)
-    }
-}
-
-#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq)]
-pub struct FunctionTypeId {
-    file_id: FileId,
-    func_id: ModuleFunctionTypeId,
-}
-
-#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq)]
-pub struct ClassTypeId {
-    file_id: FileId,
-    class_id: ModuleClassTypeId,
-}
-
-impl ClassTypeId {
-    fn get_own_class_member<Db>(self, db: &Db, name: &Name) -> QueryResult<Option<Type>>
-    where
-        Db: SemanticDb + HasJar<SemanticJar>,
-    {
-        // TODO: this should distinguish instance-only members (e.g. `x: int`) and not return them
-        let ClassType { scope_id, .. } = *db.jar()?.type_store.get_class(self);
-        let table = db.symbol_table(self.file_id)?;
-        if let Some(symbol_id) = table.symbol_id_by_name(scope_id, name) {
-            Ok(Some(db.infer_symbol_type(self.file_id, symbol_id)?))
-        } else {
-            Ok(None)
-        }
-    }
-
-    // TODO: get_own_instance_member, get_class_member, get_instance_member
-}
-
-#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq)]
-pub struct UnionTypeId {
-    file_id: FileId,
-    union_id: ModuleUnionTypeId,
-}
-
-#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq)]
-pub struct IntersectionTypeId {
-    file_id: FileId,
-    intersection_id: ModuleIntersectionTypeId,
-}
-
-#[newtype_index]
-struct ModuleFunctionTypeId;
-
-#[newtype_index]
-struct ModuleClassTypeId;
-
-#[newtype_index]
-struct ModuleUnionTypeId;
-
-#[newtype_index]
-struct ModuleIntersectionTypeId;
-
-#[derive(Debug)]
-struct ModuleTypeStore {
-    file_id: FileId,
-    /// arena of all function types defined in this module
-    functions: IndexVec<ModuleFunctionTypeId, FunctionType>,
-    /// arena of all class types defined in this module
-    classes: IndexVec<ModuleClassTypeId, ClassType>,
-    /// arenda of all union types created in this module
-    unions: IndexVec<ModuleUnionTypeId, UnionType>,
-    /// arena of all intersection types created in this module
-    intersections: IndexVec<ModuleIntersectionTypeId, IntersectionType>,
-    /// cached types of symbols in this module
-    symbol_types: FxHashMap<SymbolId, Type>,
-    /// cached types of AST nodes in this module
-    node_types: FxHashMap<NodeKey, Type>,
-}
-
-impl ModuleTypeStore {
-    fn new(file_id: FileId) -> Self {
-        Self {
-            file_id,
-            functions: IndexVec::default(),
-            classes: IndexVec::default(),
-            unions: IndexVec::default(),
-            intersections: IndexVec::default(),
-            symbol_types: FxHashMap::default(),
-            node_types: FxHashMap::default(),
-        }
-    }
-
-    fn add_function(&mut self, name: &str, decorators: Vec<Type>) -> FunctionTypeId {
-        let func_id = self.functions.push(FunctionType {
-            name: Name::new(name),
-            decorators,
-        });
-        FunctionTypeId {
-            file_id: self.file_id,
-            func_id,
-        }
-    }
-
-    fn add_class(&mut self, name: &str, scope_id: ScopeId, bases: Vec<Type>) -> ClassTypeId {
-        let class_id = self.classes.push(ClassType {
-            name: Name::new(name),
-            scope_id,
-            // TODO: if no bases are given, that should imply [object]
-            bases,
-        });
-        ClassTypeId {
-            file_id: self.file_id,
-            class_id,
-        }
-    }
-
-    fn add_union(&mut self, elems: &[Type]) -> UnionTypeId {
-        let union_id = self.unions.push(UnionType {
-            elements: elems.iter().copied().collect(),
-        });
-        UnionTypeId {
-            file_id: self.file_id,
-            union_id,
-        }
-    }
-
-    fn add_intersection(&mut self, positive: &[Type], negative: &[Type]) -> IntersectionTypeId {
-        let intersection_id = self.intersections.push(IntersectionType {
-            positive: positive.iter().copied().collect(),
-            negative: negative.iter().copied().collect(),
-        });
-        IntersectionTypeId {
-            file_id: self.file_id,
-            intersection_id,
-        }
-    }
-
-    fn get_function(&self, func_id: ModuleFunctionTypeId) -> &FunctionType {
-        &self.functions[func_id]
-    }
-
-    fn get_class(&self, class_id: ModuleClassTypeId) -> &ClassType {
-        &self.classes[class_id]
-    }
-
-    fn get_union(&self, union_id: ModuleUnionTypeId) -> &UnionType {
-        &self.unions[union_id]
-    }
-
-    fn get_intersection(&self, intersection_id: ModuleIntersectionTypeId) -> &IntersectionType {
-        &self.intersections[intersection_id]
-    }
-}
-
-#[derive(Copy, Clone, Debug)]
-struct DisplayType<'a> {
-    ty: &'a Type,
-    store: &'a TypeStore,
-}
-
-impl std::fmt::Display for DisplayType<'_> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self.ty {
-            Type::Any => f.write_str("Any"),
-            Type::Never => f.write_str("Never"),
-            Type::Unknown => f.write_str("Unknown"),
-            Type::Unbound => f.write_str("Unbound"),
-            // TODO functions and classes should display using a fully qualified name
-            Type::Class(class_id) => {
-                f.write_str("Literal[")?;
-                f.write_str(self.store.get_class(*class_id).name())?;
-                f.write_str("]")
-            }
-            Type::Instance(class_id) => f.write_str(self.store.get_class(*class_id).name()),
-            Type::Function(func_id) => f.write_str(self.store.get_function(*func_id).name()),
-            Type::Union(union_id) => self
-                .store
-                .get_module(union_id.file_id)
-                .get_union(union_id.union_id)
-                .display(f, self.store),
-            Type::Intersection(int_id) => self
-                .store
-                .get_module(int_id.file_id)
-                .get_intersection(int_id.intersection_id)
-                .display(f, self.store),
-        }
-    }
-}
-
-#[derive(Debug)]
-pub(crate) struct ClassType {
-    /// Name of the class at definition
-    name: Name,
-    /// `ScopeId` of the class body
-    pub(crate) scope_id: ScopeId,
-    /// Types of all class bases
-    bases: Vec<Type>,
-}
-
-impl ClassType {
-    fn name(&self) -> &str {
-        self.name.as_str()
-    }
-
-    fn bases(&self) -> &[Type] {
-        self.bases.as_slice()
-    }
-}
-
-#[derive(Debug)]
-pub(crate) struct FunctionType {
-    name: Name,
-    decorators: Vec<Type>,
-}
-
-impl FunctionType {
-    fn name(&self) -> &str {
-        self.name.as_str()
-    }
-
-    fn decorators(&self) -> &[Type] {
-        self.decorators.as_slice()
-    }
-}
-
-#[derive(Debug)]
-pub(crate) struct UnionType {
-    // the union type includes values in any of these types
-    elements: FxIndexSet<Type>,
-}
-
-impl UnionType {
-    fn display(&self, f: &mut std::fmt::Formatter<'_>, store: &TypeStore) -> std::fmt::Result {
-        f.write_str("(")?;
-        let mut first = true;
-        for ty in &self.elements {
-            if !first {
-                f.write_str(" | ")?;
-            };
-            first = false;
-            write!(f, "{}", ty.display(store))?;
-        }
-        f.write_str(")")
-    }
-}
-
-// Negation types aren't expressible in annotations, and are most likely to arise from type
-// narrowing along with intersections (e.g. `if not isinstance(...)`), so we represent them
-// directly in intersections rather than as a separate type. This sacrifices some efficiency in the
-// case where a Not appears outside an intersection (unclear when that could even happen, but we'd
-// have to represent it as a single-element intersection if it did) in exchange for better
-// efficiency in the not-within-intersection case.
-#[derive(Debug)]
-pub(crate) struct IntersectionType {
-    // the intersection type includes only values in all of these types
-    positive: FxIndexSet<Type>,
-    // negated elements of the intersection, e.g.
-    negative: FxIndexSet<Type>,
-}
-
-impl IntersectionType {
-    fn display(&self, f: &mut std::fmt::Formatter<'_>, store: &TypeStore) -> std::fmt::Result {
-        f.write_str("(")?;
-        let mut first = true;
-        for (neg, ty) in self
-            .positive
-            .iter()
-            .map(|ty| (false, ty))
-            .chain(self.negative.iter().map(|ty| (true, ty)))
-        {
-            if !first {
-                f.write_str(" & ")?;
-            };
-            first = false;
-            if neg {
-                f.write_str("~")?;
-            };
-            write!(f, "{}", ty.display(store))?;
-        }
-        f.write_str(")")
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::files::Files;
-    use crate::symbols::SymbolTable;
-    use crate::types::{Type, TypeStore};
-    use crate::FxIndexSet;
-    use std::path::Path;
-
-    #[test]
-    fn add_class() {
-        let store = TypeStore::default();
-        let files = Files::default();
-        let file_id = files.intern(Path::new("/foo"));
-        let id = store.add_class(file_id, "C", SymbolTable::root_scope_id(), Vec::new());
-        assert_eq!(store.get_class(id).name(), "C");
-        let inst = Type::Instance(id);
-        assert_eq!(format!("{}", inst.display(&store)), "C");
-    }
-
-    #[test]
-    fn add_function() {
-        let store = TypeStore::default();
-        let files = Files::default();
-        let file_id = files.intern(Path::new("/foo"));
-        let id = store.add_function(file_id, "func", vec![Type::Unknown]);
-        assert_eq!(store.get_function(id).name(), "func");
-        assert_eq!(store.get_function(id).decorators(), vec![Type::Unknown]);
-        let func = Type::Function(id);
-        assert_eq!(format!("{}", func.display(&store)), "func");
-    }
-
-    #[test]
-    fn add_union() {
-        let mut store = TypeStore::default();
-        let files = Files::default();
-        let file_id = files.intern(Path::new("/foo"));
-        let c1 = store.add_class(file_id, "C1", SymbolTable::root_scope_id(), Vec::new());
-        let c2 = store.add_class(file_id, "C2", SymbolTable::root_scope_id(), Vec::new());
-        let elems = vec![Type::Instance(c1), Type::Instance(c2)];
-        let id = store.add_union(file_id, &elems);
-        assert_eq!(
-            store.get_union(id).elements,
-            elems.into_iter().collect::<FxIndexSet<_>>()
-        );
-        let union = Type::Union(id);
-        assert_eq!(format!("{}", union.display(&store)), "(C1 | C2)");
-    }
-
-    #[test]
-    fn add_intersection() {
-        let mut store = TypeStore::default();
-        let files = Files::default();
-        let file_id = files.intern(Path::new("/foo"));
-        let c1 = store.add_class(file_id, "C1", SymbolTable::root_scope_id(), Vec::new());
-        let c2 = store.add_class(file_id, "C2", SymbolTable::root_scope_id(), Vec::new());
-        let c3 = store.add_class(file_id, "C3", SymbolTable::root_scope_id(), Vec::new());
-        let pos = vec![Type::Instance(c1), Type::Instance(c2)];
-        let neg = vec![Type::Instance(c3)];
-        let id = store.add_intersection(file_id, &pos, &neg);
-        assert_eq!(
-            store.get_intersection(id).positive,
-            pos.into_iter().collect::<FxIndexSet<_>>()
-        );
-        assert_eq!(
-            store.get_intersection(id).negative,
-            neg.into_iter().collect::<FxIndexSet<_>>()
-        );
-        let intersection = Type::Intersection(id);
-        assert_eq!(
-            format!("{}", intersection.display(&store)),
-            "(C1 & C2 & ~C3)"
-        );
-    }
-}

crates/red_knot/src/types/infer.rs

@@ -1,265 +0,0 @@
-#![allow(dead_code)]
-
-use ruff_python_ast::AstNode;
-
-use crate::db::{HasJar, QueryResult, SemanticDb, SemanticJar};
-use crate::module::ModuleName;
-use crate::symbols::{ClassDefinition, Definition, ImportFromDefinition, SymbolId};
-use crate::types::Type;
-use crate::FileId;
-use ruff_python_ast as ast;
-
-// FIXME: Figure out proper dead-lock free synchronisation now that this takes `&db` instead of `&mut db`.
-#[tracing::instrument(level = "trace", skip(db))]
-pub fn infer_symbol_type<Db>(db: &Db, file_id: FileId, symbol_id: SymbolId) -> QueryResult<Type>
-where
-    Db: SemanticDb + HasJar<SemanticJar>,
-{
-    let symbols = db.symbol_table(file_id)?;
-    let defs = symbols.definitions(symbol_id);
-
-    if let Some(ty) = db
-        .jar()?
-        .type_store
-        .get_cached_symbol_type(file_id, symbol_id)
-    {
-        return Ok(ty);
-    }
-
-    // TODO handle multiple defs, conditional defs...
-    assert_eq!(defs.len(), 1);
-    let type_store = &db.jar()?.type_store;
-
-    let ty = match &defs[0] {
-        Definition::ImportFrom(ImportFromDefinition {
-            module,
-            name,
-            level,
-        }) => {
-            // TODO relative imports
-            assert!(matches!(level, 0));
-            let module_name = ModuleName::new(module.as_ref().expect("TODO relative imports"));
-            if let Some(module) = db.resolve_module(module_name)? {
-                let remote_file_id = module.path(db)?.file();
-                let remote_symbols = db.symbol_table(remote_file_id)?;
-                if let Some(remote_symbol_id) = remote_symbols.root_symbol_id_by_name(name) {
-                    db.infer_symbol_type(remote_file_id, remote_symbol_id)?
-                } else {
-                    Type::Unknown
-                }
-            } else {
-                Type::Unknown
-            }
-        }
-        Definition::ClassDef(ClassDefinition { node_key, scope_id }) => {
-            if let Some(ty) = type_store.get_cached_node_type(file_id, node_key.erased()) {
-                ty
-            } else {
-                let parsed = db.parse(file_id)?;
-                let ast = parsed.ast();
-                let node = node_key.resolve_unwrap(ast.as_any_node_ref());
-
-                let mut bases = Vec::with_capacity(node.bases().len());
-
-                for base in node.bases() {
-                    bases.push(infer_expr_type(db, file_id, base)?);
-                }
-
-                let ty =
-                    Type::Class(type_store.add_class(file_id, &node.name.id, *scope_id, bases));
-                type_store.cache_node_type(file_id, *node_key.erased(), ty);
-                ty
-            }
-        }
-        Definition::FunctionDef(node_key) => {
-            if let Some(ty) = type_store.get_cached_node_type(file_id, node_key.erased()) {
-                ty
-            } else {
-                let parsed = db.parse(file_id)?;
-                let ast = parsed.ast();
-                let node = node_key
-                    .resolve(ast.as_any_node_ref())
-                    .expect("node key should resolve");
-
-                let decorator_tys = node
-                    .decorator_list
-                    .iter()
-                    .map(|decorator| infer_expr_type(db, file_id, &decorator.expression))
-                    .collect::<QueryResult<_>>()?;
-
-                let ty = type_store
-                    .add_function(file_id, &node.name.id, decorator_tys)
-                    .into();
-                type_store.cache_node_type(file_id, *node_key.erased(), ty);
-                ty
-            }
-        }
-        Definition::Assignment(node_key) => {
-            let parsed = db.parse(file_id)?;
-            let ast = parsed.ast();
-            let node = node_key.resolve_unwrap(ast.as_any_node_ref());
-            // TODO handle unpacking assignment correctly
-            infer_expr_type(db, file_id, &node.value)?
-        }
-        _ => todo!("other kinds of definitions"),
-    };
-
-    type_store.cache_symbol_type(file_id, symbol_id, ty);
-
-    // TODO record dependencies
-    Ok(ty)
-}
-
-fn infer_expr_type<Db>(db: &Db, file_id: FileId, expr: &ast::Expr) -> QueryResult<Type>
-where
-    Db: SemanticDb + HasJar<SemanticJar>,
-{
-    // TODO cache the resolution of the type on the node
-    let symbols = db.symbol_table(file_id)?;
-    match expr {
-        ast::Expr::Name(name) => {
-            if let Some(symbol_id) = symbols.root_symbol_id_by_name(&name.id) {
-                db.infer_symbol_type(file_id, symbol_id)
-            } else {
-                Ok(Type::Unknown)
-            }
-        }
-        _ => todo!("full expression type resolution"),
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::db::tests::TestDb;
-    use crate::db::{HasJar, SemanticDb, SemanticJar};
-    use crate::module::{ModuleName, ModuleSearchPath, ModuleSearchPathKind};
-    use crate::types::Type;
-    use crate::Name;
-
-    // TODO with virtual filesystem we shouldn't have to write files to disk for these
-    // tests
-
-    struct TestCase {
-        temp_dir: tempfile::TempDir,
-        db: TestDb,
-
-        src: ModuleSearchPath,
-    }
-
-    fn create_test() -> std::io::Result<TestCase> {
-        let temp_dir = tempfile::tempdir()?;
-
-        let src = temp_dir.path().join("src");
-        std::fs::create_dir(&src)?;
-        let src = ModuleSearchPath::new(src.canonicalize()?, ModuleSearchPathKind::FirstParty);
-
-        let roots = vec![src.clone()];
-
-        let mut db = TestDb::default();
-        db.set_module_search_paths(roots);
-
-        Ok(TestCase { temp_dir, db, src })
-    }
-
-    #[test]
-    fn follow_import_to_class() -> anyhow::Result<()> {
-        let case = create_test()?;
-        let db = &case.db;
-
-        let a_path = case.src.path().join("a.py");
-        let b_path = case.src.path().join("b.py");
-        std::fs::write(a_path, "from b import C as D; E = D")?;
-        std::fs::write(b_path, "class C: pass")?;
-        let a_file = db
-            .resolve_module(ModuleName::new("a"))?
-            .expect("module should be found")
-            .path(db)?
-            .file();
-        let a_syms = db.symbol_table(a_file)?;
-        let e_sym = a_syms
-            .root_symbol_id_by_name("E")
-            .expect("E symbol should be found");
-
-        let ty = db.infer_symbol_type(a_file, e_sym)?;
-
-        let jar = HasJar::<SemanticJar>::jar(db)?;
-        assert!(matches!(ty, Type::Class(_)));
-        assert_eq!(format!("{}", ty.display(&jar.type_store)), "Literal[C]");
-
-        Ok(())
-    }
-
-    #[test]
-    fn resolve_base_class_by_name() -> anyhow::Result<()> {
-        let case = create_test()?;
-        let db = &case.db;
-
-        let path = case.src.path().join("mod.py");
-        std::fs::write(path, "class Base: pass\nclass Sub(Base): pass")?;
-        let file = db
-            .resolve_module(ModuleName::new("mod"))?
-            .expect("module should be found")
-            .path(db)?
-            .file();
-        let syms = db.symbol_table(file)?;
-        let sym = syms
-            .root_symbol_id_by_name("Sub")
-            .expect("Sub symbol should be found");
-
-        let ty = db.infer_symbol_type(file, sym)?;
-
-        let Type::Class(class_id) = ty else {
-            panic!("Sub is not a Class")
-        };
-        let jar = HasJar::<SemanticJar>::jar(db)?;
-        let base_names: Vec<_> = jar
-            .type_store
-            .get_class(class_id)
-            .bases()
-            .iter()
-            .map(|base_ty| format!("{}", base_ty.display(&jar.type_store)))
-            .collect();
-
-        assert_eq!(base_names, vec!["Literal[Base]"]);
-
-        Ok(())
-    }
-
-    #[test]
-    fn resolve_method() -> anyhow::Result<()> {
-        let case = create_test()?;
-        let db = &case.db;
-
-        let path = case.src.path().join("mod.py");
-        std::fs::write(path, "class C:\n  def f(self): pass")?;
-        let file = db
-            .resolve_module(ModuleName::new("mod"))?
-            .expect("module should be found")
-            .path(db)?
-            .file();
-        let syms = db.symbol_table(file)?;
-        let sym = syms
-            .root_symbol_id_by_name("C")
-            .expect("C symbol should be found");
-
-        let ty = db.infer_symbol_type(file, sym)?;
-
-        let Type::Class(class_id) = ty else {
-            panic!("C is not a Class");
-        };
-
-        let member_ty = class_id
-            .get_own_class_member(db, &Name::new("f"))
-            .expect("C.f to resolve");
-
-        let Some(Type::Function(func_id)) = member_ty else {
-            panic!("C.f is not a Function");
-        };
-
-        let jar = HasJar::<SemanticJar>::jar(db)?;
-        let function = jar.type_store.get_function(func_id);
-        assert_eq!(function.name(), "f");
-
-        Ok(())
-    }
-}

crates/red_knot/src/typeshed_versions.rs

@@ -0,0 +1,526 @@
+use std::collections::BTreeMap;
+use std::fmt;
+use std::num::{NonZeroU16, NonZeroUsize};
+use std::ops::{RangeFrom, RangeInclusive};
+use std::str::FromStr;
+
+use rustc_hash::FxHashMap;
+use smol_str::SmolStr;
+
+use ruff_python_stdlib::identifiers::is_identifier;
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct TypeshedVersionsParseError {
+    line_number: NonZeroU16,
+    reason: TypeshedVersionsParseErrorKind,
+}
+
+impl fmt::Display for TypeshedVersionsParseError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let TypeshedVersionsParseError {
+            line_number,
+            reason,
+        } = self;
+        write!(
+            f,
+            "Error while parsing line {line_number} of typeshed's VERSIONS file: {reason}"
+        )
+    }
+}
+
+impl std::error::Error for TypeshedVersionsParseError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        if let TypeshedVersionsParseErrorKind::IntegerParsingFailure { err, .. } = &self.reason {
+            Some(err)
+        } else {
+            None
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum TypeshedVersionsParseErrorKind {
+    TooManyLines(NonZeroUsize),
+    UnexpectedNumberOfColons,
+    InvalidModuleName(String),
+    UnexpectedNumberOfHyphens,
+    UnexpectedNumberOfPeriods(String),
+    IntegerParsingFailure {
+        version: String,
+        err: std::num::ParseIntError,
+    },
+}
+
+impl fmt::Display for TypeshedVersionsParseErrorKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::TooManyLines(num_lines) => write!(
+                f,
+                "File has too many lines ({num_lines}); maximum allowed is {}",
+                NonZeroU16::MAX
+            ),
+            Self::UnexpectedNumberOfColons => {
+                f.write_str("Expected every non-comment line to have exactly one colon")
+            }
+            Self::InvalidModuleName(name) => write!(
+                f,
+                "Expected all components of '{name}' to be valid Python identifiers"
+            ),
+            Self::UnexpectedNumberOfHyphens => {
+                f.write_str("Expected every non-comment line to have exactly one '-' character")
+            }
+            Self::UnexpectedNumberOfPeriods(format) => write!(
+                f,
+                "Expected all versions to be in the form {{MAJOR}}.{{MINOR}}; got '{format}'"
+            ),
+            Self::IntegerParsingFailure { version, err } => write!(
+                f,
+                "Failed to convert '{version}' to a pair of integers due to {err}",
+            ),
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct TypeshedVersions(FxHashMap<SmolStr, PyVersionRange>);
+
+impl TypeshedVersions {
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    pub fn contains_module(&self, module_name: impl Into<SmolStr>) -> bool {
+        self.0.contains_key(&module_name.into())
+    }
+
+    pub fn module_exists_on_version(
+        &self,
+        module: impl Into<SmolStr>,
+        version: impl Into<PyVersion>,
+    ) -> bool {
+        let version = version.into();
+        let mut module: Option<SmolStr> = Some(module.into());
+        while let Some(module_to_try) = module {
+            if let Some(range) = self.0.get(&module_to_try) {
+                return range.contains(version);
+            }
+            module = module_to_try
+                .rsplit_once('.')
+                .map(|(parent, _)| SmolStr::new(parent));
+        }
+        false
+    }
+}
+
+impl FromStr for TypeshedVersions {
+    type Err = TypeshedVersionsParseError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut map = FxHashMap::default();
+
+        for (line_index, line) in s.lines().enumerate() {
+            // humans expect line numbers to be 1-indexed
+            let line_number = NonZeroUsize::new(line_index.saturating_add(1)).unwrap();
+
+            let Ok(line_number) = NonZeroU16::try_from(line_number) else {
+                return Err(TypeshedVersionsParseError {
+                    line_number: NonZeroU16::MAX,
+                    reason: TypeshedVersionsParseErrorKind::TooManyLines(line_number),
+                });
+            };
+
+            let Some(content) = line.split('#').map(str::trim).next() else {
+                continue;
+            };
+            if content.is_empty() {
+                continue;
+            }
+
+            let mut parts = content.split(':').map(str::trim);
+            let (Some(module_name), Some(rest), None) = (parts.next(), parts.next(), parts.next())
+            else {
+                return Err(TypeshedVersionsParseError {
+                    line_number,
+                    reason: TypeshedVersionsParseErrorKind::UnexpectedNumberOfColons,
+                });
+            };
+
+            let module_name = SmolStr::new(module_name);
+            if !module_name.split('.').all(is_identifier) {
+                return Err(TypeshedVersionsParseError {
+                    line_number,
+                    reason: TypeshedVersionsParseErrorKind::InvalidModuleName(
+                        module_name.to_string(),
+                    ),
+                });
+            }
+
+            match PyVersionRange::from_str(rest) {
+                Ok(version) => map.insert(module_name, version),
+                Err(reason) => {
+                    return Err(TypeshedVersionsParseError {
+                        line_number,
+                        reason,
+                    })
+                }
+            };
+        }
+
+        Ok(Self(map))
+    }
+}
+
+impl fmt::Display for TypeshedVersions {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let sorted_items: BTreeMap<&SmolStr, &PyVersionRange> = self.0.iter().collect();
+        for (module_name, range) in sorted_items {
+            writeln!(f, "{module_name}: {range}")?;
+        }
+        Ok(())
+    }
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+enum PyVersionRange {
+    AvailableFrom(RangeFrom<PyVersion>),
+    AvailableWithin(RangeInclusive<PyVersion>),
+}
+
+impl PyVersionRange {
+    fn contains(&self, version: PyVersion) -> bool {
+        match self {
+            Self::AvailableFrom(inner) => inner.contains(&version),
+            Self::AvailableWithin(inner) => inner.contains(&version),
+        }
+    }
+}
+
+impl FromStr for PyVersionRange {
+    type Err = TypeshedVersionsParseErrorKind;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut parts = s.split('-').map(str::trim);
+        match (parts.next(), parts.next(), parts.next()) {
+            (Some(lower), Some(""), None) => Ok(Self::AvailableFrom((lower.parse()?)..)),
+            (Some(lower), Some(upper), None) => {
+                Ok(Self::AvailableWithin((lower.parse()?)..=(upper.parse()?)))
+            }
+            _ => Err(TypeshedVersionsParseErrorKind::UnexpectedNumberOfHyphens),
+        }
+    }
+}
+
+impl fmt::Display for PyVersionRange {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::AvailableFrom(range_from) => write!(f, "{}-", range_from.start),
+            Self::AvailableWithin(range_inclusive) => {
+                write!(f, "{}-{}", range_inclusive.start(), range_inclusive.end())
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub struct PyVersion {
+    major: u8,
+    minor: u8,
+}
+
+impl FromStr for PyVersion {
+    type Err = TypeshedVersionsParseErrorKind;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut parts = s.split('.').map(str::trim);
+        let (Some(major), Some(minor), None) = (parts.next(), parts.next(), parts.next()) else {
+            return Err(TypeshedVersionsParseErrorKind::UnexpectedNumberOfPeriods(
+                s.to_string(),
+            ));
+        };
+        let major = match u8::from_str(major) {
+            Ok(major) => major,
+            Err(err) => {
+                return Err(TypeshedVersionsParseErrorKind::IntegerParsingFailure {
+                    version: s.to_string(),
+                    err,
+                })
+            }
+        };
+        let minor = match u8::from_str(minor) {
+            Ok(minor) => minor,
+            Err(err) => {
+                return Err(TypeshedVersionsParseErrorKind::IntegerParsingFailure {
+                    version: s.to_string(),
+                    err,
+                })
+            }
+        };
+        Ok(Self { major, minor })
+    }
+}
+
+impl fmt::Display for PyVersion {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let PyVersion { major, minor } = self;
+        write!(f, "{major}.{minor}")
+    }
+}
+
+// TODO: unify with the PythonVersion enum in the linter/formatter crates?
+#[derive(Copy, Clone, Hash, Debug, PartialEq, Eq, PartialOrd, Ord, Default)]
+pub enum SupportedPyVersion {
+    Py37,
+    #[default]
+    Py38,
+    Py39,
+    Py310,
+    Py311,
+    Py312,
+    Py313,
+}
+
+impl From<SupportedPyVersion> for PyVersion {
+    fn from(value: SupportedPyVersion) -> Self {
+        match value {
+            SupportedPyVersion::Py37 => PyVersion { major: 3, minor: 7 },
+            SupportedPyVersion::Py38 => PyVersion { major: 3, minor: 8 },
+            SupportedPyVersion::Py39 => PyVersion { major: 3, minor: 9 },
+            SupportedPyVersion::Py310 => PyVersion {
+                major: 3,
+                minor: 10,
+            },
+            SupportedPyVersion::Py311 => PyVersion {
+                major: 3,
+                minor: 11,
+            },
+            SupportedPyVersion::Py312 => PyVersion {
+                major: 3,
+                minor: 12,
+            },
+            SupportedPyVersion::Py313 => PyVersion {
+                major: 3,
+                minor: 13,
+            },
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::num::{IntErrorKind, NonZeroU16};
+
+    use super::*;
+
+    use insta::assert_snapshot;
+
+    #[allow(unsafe_code)]
+    const ONE: NonZeroU16 = unsafe { NonZeroU16::new_unchecked(1) };
+
+    #[test]
+    fn can_parse_vendored_versions_file() {
+        let versions_data = include_str!(concat!(
+            env!("CARGO_MANIFEST_DIR"),
+            "/vendor/typeshed/stdlib/VERSIONS"
+        ));
+
+        let versions = TypeshedVersions::from_str(versions_data).unwrap();
+        assert!(versions.len() > 100);
+        assert!(versions.len() < 1000);
+
+        assert!(versions.contains_module("asyncio"));
+        assert!(versions.module_exists_on_version("asyncio", SupportedPyVersion::Py310));
+
+        assert!(versions.contains_module("asyncio.staggered"));
+        assert!(versions.module_exists_on_version("asyncio.staggered", SupportedPyVersion::Py38));
+        assert!(!versions.module_exists_on_version("asyncio.staggered", SupportedPyVersion::Py37));
+
+        assert!(versions.contains_module("audioop"));
+        assert!(versions.module_exists_on_version("audioop", SupportedPyVersion::Py312));
+        assert!(!versions.module_exists_on_version("audioop", SupportedPyVersion::Py313));
+    }
+
+    #[test]
+    fn can_parse_mock_versions_file() {
+        const VERSIONS: &str = "\
+# a comment
+    # some more comment
+# yet more comment
+
+
+# and some more comment
+
+bar: 2.7-3.10
+
+# more comment
+bar.baz: 3.1-3.9
+foo: 3.8-   # trailing comment
+";
+        let parsed_versions = TypeshedVersions::from_str(VERSIONS).unwrap();
+        assert_eq!(parsed_versions.len(), 3);
+        assert_snapshot!(parsed_versions.to_string(), @r###"
+        bar: 2.7-3.10
+        bar.baz: 3.1-3.9
+        foo: 3.8-
+        "###
+        );
+
+        assert!(parsed_versions.contains_module("foo"));
+        assert!(!parsed_versions.module_exists_on_version("foo", SupportedPyVersion::Py37));
+        assert!(parsed_versions.module_exists_on_version("foo", SupportedPyVersion::Py38));
+        assert!(parsed_versions.module_exists_on_version("foo", SupportedPyVersion::Py311));
+
+        assert!(parsed_versions.contains_module("bar"));
+        assert!(parsed_versions.module_exists_on_version("bar", SupportedPyVersion::Py37));
+        assert!(parsed_versions.module_exists_on_version("bar", SupportedPyVersion::Py310));
+        assert!(!parsed_versions.module_exists_on_version("bar", SupportedPyVersion::Py311));
+
+        assert!(parsed_versions.contains_module("bar.baz"));
+        assert!(parsed_versions.module_exists_on_version("bar.baz", SupportedPyVersion::Py37));
+        assert!(parsed_versions.module_exists_on_version("bar.baz", SupportedPyVersion::Py39));
+        assert!(!parsed_versions.module_exists_on_version("bar.baz", SupportedPyVersion::Py310));
+
+        assert!(!parsed_versions.contains_module("spam"));
+        assert!(!parsed_versions.module_exists_on_version("spam", SupportedPyVersion::Py37));
+        assert!(!parsed_versions.module_exists_on_version("spam", SupportedPyVersion::Py313));
+    }
+
+    #[test]
+    fn invalid_huge_versions_file() {
+        let offset = 100;
+        let too_many = u16::MAX as usize + offset;
+
+        let mut massive_versions_file = String::new();
+        for i in 0..too_many {
+            massive_versions_file.push_str(&format!("x{i}: 3.8-\n"));
+        }
+
+        assert_eq!(
+            TypeshedVersions::from_str(&massive_versions_file),
+            Err(TypeshedVersionsParseError {
+                line_number: NonZeroU16::MAX,
+                reason: TypeshedVersionsParseErrorKind::TooManyLines(
+                    NonZeroUsize::new(too_many + 1 - offset).unwrap()
+                )
+            })
+        );
+    }
+
+    #[test]
+    fn invalid_typeshed_versions_bad_colon_number() {
+        assert_eq!(
+            TypeshedVersions::from_str("foo 3.7"),
+            Err(TypeshedVersionsParseError {
+                line_number: ONE,
+                reason: TypeshedVersionsParseErrorKind::UnexpectedNumberOfColons
+            })
+        );
+        assert_eq!(
+            TypeshedVersions::from_str("foo:: 3.7"),
+            Err(TypeshedVersionsParseError {
+                line_number: ONE,
+                reason: TypeshedVersionsParseErrorKind::UnexpectedNumberOfColons
+            })
+        );
+    }
+
+    #[test]
+    fn invalid_typeshed_versions_non_identifier_modules() {
+        assert_eq!(
+            TypeshedVersions::from_str("not!an!identifier!: 3.7"),
+            Err(TypeshedVersionsParseError {
+                line_number: ONE,
+                reason: TypeshedVersionsParseErrorKind::InvalidModuleName(
+                    "not!an!identifier!".to_string()
+                )
+            })
+        );
+        assert_eq!(
+            TypeshedVersions::from_str("(also_not).(an_identifier): 3.7"),
+            Err(TypeshedVersionsParseError {
+                line_number: ONE,
+                reason: TypeshedVersionsParseErrorKind::InvalidModuleName(
+                    "(also_not).(an_identifier)".to_string()
+                )
+            })
+        );
+    }
+
+    #[test]
+    fn invalid_typeshed_versions_bad_hyphen_number() {
+        assert_eq!(
+            TypeshedVersions::from_str("foo: 3.8"),
+            Err(TypeshedVersionsParseError {
+                line_number: ONE,
+                reason: TypeshedVersionsParseErrorKind::UnexpectedNumberOfHyphens
+            })
+        );
+        assert_eq!(
+            TypeshedVersions::from_str("foo: 3.8--"),
+            Err(TypeshedVersionsParseError {
+                line_number: ONE,
+                reason: TypeshedVersionsParseErrorKind::UnexpectedNumberOfHyphens
+            })
+        );
+        assert_eq!(
+            TypeshedVersions::from_str("foo: 3.8--3.9"),
+            Err(TypeshedVersionsParseError {
+                line_number: ONE,
+                reason: TypeshedVersionsParseErrorKind::UnexpectedNumberOfHyphens
+            })
+        );
+    }
+
+    #[test]
+    fn invalid_typeshed_versions_bad_period_number() {
+        assert_eq!(
+            TypeshedVersions::from_str("foo: 38-"),
+            Err(TypeshedVersionsParseError {
+                line_number: ONE,
+                reason: TypeshedVersionsParseErrorKind::UnexpectedNumberOfPeriods("38".to_string())
+            })
+        );
+        assert_eq!(
+            TypeshedVersions::from_str("foo: 3..8-"),
+            Err(TypeshedVersionsParseError {
+                line_number: ONE,
+                reason: TypeshedVersionsParseErrorKind::UnexpectedNumberOfPeriods(
+                    "3..8".to_string()
+                )
+            })
+        );
+        assert_eq!(
+            TypeshedVersions::from_str("foo: 3.8-3..11"),
+            Err(TypeshedVersionsParseError {
+                line_number: ONE,
+                reason: TypeshedVersionsParseErrorKind::UnexpectedNumberOfPeriods(
+                    "3..11".to_string()
+                )
+            })
+        );
+    }
+
+    #[test]
+    fn invalid_typeshed_versions_non_digits() {
+        let err = TypeshedVersions::from_str("foo: 1.two-").unwrap_err();
+        assert_eq!(err.line_number, ONE);
+        let TypeshedVersionsParseErrorKind::IntegerParsingFailure { version, err } = err.reason
+        else {
+            panic!()
+        };
+        assert_eq!(version, "1.two".to_string());
+        assert_eq!(*err.kind(), IntErrorKind::InvalidDigit);
+
+        let err = TypeshedVersions::from_str("foo: 3.8-four.9").unwrap_err();
+        assert_eq!(err.line_number, ONE);
+        let TypeshedVersionsParseErrorKind::IntegerParsingFailure { version, err } = err.reason
+        else {
+            panic!()
+        };
+        assert_eq!(version, "four.9".to_string());
+        assert_eq!(*err.kind(), IntErrorKind::InvalidDigit);
+    }
+}

crates/red_knot/vendor/typeshed/LICENSE

@@ -0,0 +1,237 @@
+The "typeshed" project is licensed under the terms of the Apache license, as
+reproduced below.
+
+= = = = =
+
+Apache License
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+
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+      the terms of any separate license agreement you may have executed
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+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
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+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
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+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
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+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
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+      file or class name and description of purpose be included on the
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+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+= = = = =
+
+Parts of typeshed are licensed under different licenses (like the MIT
+license), reproduced below.
+
+= = = = =
+
+The MIT License
+
+Copyright (c) 2015 Jukka Lehtosalo and contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
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+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+
+= = = = =

crates/red_knot/vendor/typeshed/README.md

@@ -0,0 +1,124 @@
+# typeshed
+
+[![Tests](https://github.com/python/typeshed/actions/workflows/tests.yml/badge.svg)](https://github.com/python/typeshed/actions/workflows/tests.yml)
+[![Chat at https://gitter.im/python/typing](https://badges.gitter.im/python/typing.svg)](https://gitter.im/python/typing?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Pull Requests Welcome](https://img.shields.io/badge/pull%20requests-welcome-brightgreen.svg)](https://github.com/python/typeshed/blob/main/CONTRIBUTING.md)
+
+## About
+
+Typeshed contains external type annotations for the Python standard library
+and Python builtins, as well as third party packages as contributed by
+people external to those projects.
+
+This data can e.g. be used for static analysis, type checking, type inference,
+and autocompletion.
+
+For information on how to use typeshed, read below.  Information for
+contributors can be found in [CONTRIBUTING.md](CONTRIBUTING.md).  **Please read
+it before submitting pull requests; do not report issues with annotations to
+the project the stubs are for, but instead report them here to typeshed.**
+
+Further documentation on stub files, typeshed, and Python's typing system in
+general, can also be found at https://typing.readthedocs.io/en/latest/.
+
+Typeshed supports Python versions 3.8 and up.
+
+## Using
+
+If you're just using a type checker ([mypy](https://github.com/python/mypy/),
+[pyright](https://github.com/microsoft/pyright),
+[pytype](https://github.com/google/pytype/), PyCharm, ...), as opposed to
+developing it, you don't need to interact with the typeshed repo at
+all: a copy of standard library part of typeshed is bundled with type checkers.
+And type stubs for third party packages and modules you are using can
+be installed from PyPI. For example, if you are using `html5lib` and `requests`,
+you can install the type stubs using
+
+```bash
+$ pip install types-html5lib types-requests
+```
+
+These PyPI packages follow [PEP 561](http://www.python.org/dev/peps/pep-0561/)
+and are automatically released (up to once a day) by
+[typeshed internal machinery](https://github.com/typeshed-internal/stub_uploader).
+
+Type checkers should be able to use these stub packages when installed. For more
+details, see the documentation for your type checker.
+
+### Package versioning for third-party stubs
+
+Version numbers of third-party stub packages consist of at least four parts.
+All parts of the stub version, except for the last part, correspond to the
+version of the runtime package being stubbed. For example, if the `types-foo`
+package has version `1.2.0.20240309`, this guarantees that the `types-foo` package
+contains stubs targeted against `foo==1.2.*` and tested against the latest
+version of `foo` matching that specifier. In this example, the final element
+of the version number (20240309) indicates that the stub package was pushed on
+March 9, 2024.
+
+At typeshed, we try to keep breaking changes to a minimum. However, due to the
+nature of stubs, any version bump can introduce changes that might make your
+code fail to type check.
+
+There are several strategies available for specifying the version of a stubs
+package you're using, each with its own tradeoffs:
+
+1. Use the same bounds that you use for the package being stubbed. For example,
+   if you use `requests>=2.30.0,<2.32`, you can use
+   `types-requests>=2.30.0,<2.32`. This ensures that the stubs are compatible
+   with the package you are using, but it carries a small risk of breaking
+   type checking due to changes in the stubs.
+
+   Another risk of this strategy is that stubs often lag behind
+   the package being stubbed. You might want to force the package being stubbed
+   to a certain minimum version because it fixes a critical bug, but if
+   correspondingly updated stubs have not been released, your type
+   checking results may not be fully accurate.
+2. Pin the stubs to a known good version and update the pin from time to time
+   (either manually, or using a tool such as dependabot or renovate).
+
+   For example, if you use `types-requests==2.31.0.1`, you can have confidence
+   that upgrading dependencies will not break type checking. However, you will
+   miss out on improvements in the stubs that could potentially improve type
+   checking until you update the pin. This strategy also has the risk that the
+   stubs you are using might become incompatible with the package being stubbed.
+3. Don't pin the stubs. This is the option that demands the least work from
+   you when it comes to updating version pins, and has the advantage that you
+   will automatically benefit from improved stubs whenever a new version of the
+   stubs package is released. However, it carries the risk that the stubs
+   become incompatible with the package being stubbed.
+
+   For example, if a new major version of the package is released, there's a
+   chance the stubs might be updated to reflect the new version of the runtime
+   package before you update the package being stubbed.
+
+You can also switch between the different strategies as needed. For example,
+you could default to strategy (1), but fall back to strategy (2) when
+a problem arises that can't easily be fixed.
+
+### The `_typeshed` package
+
+typeshed includes a package `_typeshed` as part of the standard library.
+This package and its submodules contain utility types, but are not
+available at runtime. For more information about how to use this package,
+[see the `stdlib/_typeshed` directory](https://github.com/python/typeshed/tree/main/stdlib/_typeshed).
+
+## Discussion
+
+If you've run into behavior in the type checker that suggests the type
+stubs for a given library are incorrect or incomplete,
+we want to hear from you!
+
+Our main forum for discussion is the project's [GitHub issue
+tracker](https://github.com/python/typeshed/issues).  This is the right
+place to start a discussion of any of the above or most any other
+topic concerning the project.
+
+If you have general questions about typing with Python, or you need
+a review of your type annotations or stubs outside of typeshed, head over to
+[our discussion forum](https://github.com/python/typing/discussions).
+For less formal discussion, try the typing chat room on
+[gitter.im](https://gitter.im/python/typing).  Some typeshed maintainers
+are almost always present; feel free to find us there and we're happy
+to chat.  Substantive technical discussion will be directed to the
+issue tracker.

crates/red_knot/vendor/typeshed/source_commit.txt

@@ -0,0 +1 @@
+4b6558c12ac43cd40716cd6452fe98a632ae65d7

crates/red_knot/vendor/typeshed/stdlib/VERSIONS

@@ -0,0 +1,309 @@
+# The structure of this file is as follows:
+# - Blank lines and comments starting with `#` are ignored.
+# - Lines contain the name of a module, followed by a colon,
+#   a space, and a version range (for example: `symbol: 3.0-3.9`).
+#
+# Version ranges may be of the form "X.Y-A.B" or "X.Y-". The
+# first form means that a module was introduced in version X.Y and last
+# available in version A.B. The second form means that the module was
+# introduced in version X.Y and is still available in the latest
+# version of Python.
+#
+# If a submodule is not listed separately, it has the same lifetime as
+# its parent module.
+#
+# Python versions before 3.0 are ignored, so any module that was already
+# present in 3.0 will have "3.0" as its minimum version. Version ranges
+# for unsupported versions of Python 3 are generally accurate but we do
+# not guarantee their correctness.
+
+__future__: 3.0-
+__main__: 3.0-
+_ast: 3.0-
+_bisect: 3.0-
+_bootlocale: 3.4-3.9
+_codecs: 3.0-
+_collections_abc: 3.3-
+_compat_pickle: 3.1-
+_compression: 3.5-
+_csv: 3.0-
+_ctypes: 3.0-
+_curses: 3.0-
+_decimal: 3.3-
+_dummy_thread: 3.0-3.8
+_dummy_threading: 3.0-3.8
+_heapq: 3.0-
+_imp: 3.0-
+_json: 3.0-
+_locale: 3.0-
+_lsprof: 3.0-
+_markupbase: 3.0-
+_msi: 3.0-
+_operator: 3.4-
+_osx_support: 3.0-
+_posixsubprocess: 3.2-
+_py_abc: 3.7-
+_pydecimal: 3.5-
+_random: 3.0-
+_sitebuiltins: 3.4-
+_socket: 3.0-  # present in 3.0 at runtime, but not in typeshed
+_stat: 3.4-
+_thread: 3.0-
+_threading_local: 3.0-
+_tkinter: 3.0-
+_tracemalloc: 3.4-
+_typeshed: 3.0-  # not present at runtime, only for type checking
+_warnings: 3.0-
+_weakref: 3.0-
+_weakrefset: 3.0-
+_winapi: 3.3-
+abc: 3.0-
+aifc: 3.0-3.12
+antigravity: 3.0-
+argparse: 3.0-
+array: 3.0-
+ast: 3.0-
+asynchat: 3.0-3.11
+asyncio: 3.4-
+asyncio.mixins: 3.10-
+asyncio.exceptions: 3.8-
+asyncio.format_helpers: 3.7-
+asyncio.runners: 3.7-
+asyncio.staggered: 3.8-
+asyncio.taskgroups: 3.11-
+asyncio.threads: 3.9-
+asyncio.timeouts: 3.11-
+asyncio.trsock: 3.8-
+asyncore: 3.0-3.11
+atexit: 3.0-
+audioop: 3.0-3.12
+base64: 3.0-
+bdb: 3.0-
+binascii: 3.0-
+binhex: 3.0-3.10
+bisect: 3.0-
+builtins: 3.0-
+bz2: 3.0-
+cProfile: 3.0-
+calendar: 3.0-
+cgi: 3.0-3.12
+cgitb: 3.0-3.12
+chunk: 3.0-3.12
+cmath: 3.0-
+cmd: 3.0-
+code: 3.0-
+codecs: 3.0-
+codeop: 3.0-
+collections: 3.0-
+collections.abc: 3.3-
+colorsys: 3.0-
+compileall: 3.0-
+concurrent: 3.2-
+configparser: 3.0-
+contextlib: 3.0-
+contextvars: 3.7-
+copy: 3.0-
+copyreg: 3.0-
+crypt: 3.0-3.12
+csv: 3.0-
+ctypes: 3.0-
+curses: 3.0-
+dataclasses: 3.7-
+datetime: 3.0-
+dbm: 3.0-
+decimal: 3.0-
+difflib: 3.0-
+dis: 3.0-
+distutils: 3.0-3.11
+distutils.command.bdist_msi: 3.0-3.10
+distutils.command.bdist_wininst: 3.0-3.9
+doctest: 3.0-
+dummy_threading: 3.0-3.8
+email: 3.0-
+encodings: 3.0-
+ensurepip: 3.0-
+enum: 3.4-
+errno: 3.0-
+faulthandler: 3.3-
+fcntl: 3.0-
+filecmp: 3.0-
+fileinput: 3.0-
+fnmatch: 3.0-
+formatter: 3.0-3.9
+fractions: 3.0-
+ftplib: 3.0-
+functools: 3.0-
+gc: 3.0-
+genericpath: 3.0-
+getopt: 3.0-
+getpass: 3.0-
+gettext: 3.0-
+glob: 3.0-
+graphlib: 3.9-
+grp: 3.0-
+gzip: 3.0-
+hashlib: 3.0-
+heapq: 3.0-
+hmac: 3.0-
+html: 3.0-
+http: 3.0-
+imaplib: 3.0-
+imghdr: 3.0-3.12
+imp: 3.0-3.11
+importlib: 3.0-
+importlib._abc: 3.10-
+importlib.metadata: 3.8-
+importlib.metadata._meta: 3.10-
+importlib.readers: 3.10-
+importlib.resources: 3.7-
+importlib.resources.abc: 3.11-
+importlib.resources.readers: 3.11-
+importlib.resources.simple: 3.11-
+importlib.simple: 3.11-
+inspect: 3.0-
+io: 3.0-
+ipaddress: 3.3-
+itertools: 3.0-
+json: 3.0-
+keyword: 3.0-
+lib2to3: 3.0-3.12
+linecache: 3.0-
+locale: 3.0-
+logging: 3.0-
+lzma: 3.3-
+mailbox: 3.0-
+mailcap: 3.0-3.12
+marshal: 3.0-
+math: 3.0-
+mimetypes: 3.0-
+mmap: 3.0-
+modulefinder: 3.0-
+msilib: 3.0-3.12
+msvcrt: 3.0-
+multiprocessing: 3.0-
+multiprocessing.resource_tracker: 3.8-
+multiprocessing.shared_memory: 3.8-
+netrc: 3.0-
+nis: 3.0-3.12
+nntplib: 3.0-3.12
+nt: 3.0-
+ntpath: 3.0-
+nturl2path: 3.0-
+numbers: 3.0-
+opcode: 3.0-
+operator: 3.0-
+optparse: 3.0-
+os: 3.0-
+ossaudiodev: 3.0-3.12
+parser: 3.0-3.9
+pathlib: 3.4-
+pdb: 3.0-
+pickle: 3.0-
+pickletools: 3.0-
+pipes: 3.0-3.12
+pkgutil: 3.0-
+platform: 3.0-
+plistlib: 3.0-
+poplib: 3.0-
+posix: 3.0-
+posixpath: 3.0-
+pprint: 3.0-
+profile: 3.0-
+pstats: 3.0-
+pty: 3.0-
+pwd: 3.0-
+py_compile: 3.0-
+pyclbr: 3.0-
+pydoc: 3.0-
+pydoc_data: 3.0-
+pyexpat: 3.0-
+queue: 3.0-
+quopri: 3.0-
+random: 3.0-
+re: 3.0-
+readline: 3.0-
+reprlib: 3.0-
+resource: 3.0-
+rlcompleter: 3.0-
+runpy: 3.0-
+sched: 3.0-
+secrets: 3.6-
+select: 3.0-
+selectors: 3.4-
+shelve: 3.0-
+shlex: 3.0-
+shutil: 3.0-
+signal: 3.0-
+site: 3.0-
+smtpd: 3.0-3.11
+smtplib: 3.0-
+sndhdr: 3.0-3.12
+socket: 3.0-
+socketserver: 3.0-
+spwd: 3.0-3.12
+sqlite3: 3.0-
+sre_compile: 3.0-
+sre_constants: 3.0-
+sre_parse: 3.0-
+ssl: 3.0-
+stat: 3.0-
+statistics: 3.4-
+string: 3.0-
+stringprep: 3.0-
+struct: 3.0-
+subprocess: 3.0-
+sunau: 3.0-3.12
+symbol: 3.0-3.9
+symtable: 3.0-
+sys: 3.0-
+sys._monitoring: 3.12-  # Doesn't actually exist. See comments in the stub.
+sysconfig: 3.0-
+syslog: 3.0-
+tabnanny: 3.0-
+tarfile: 3.0-
+telnetlib: 3.0-3.12
+tempfile: 3.0-
+termios: 3.0-
+textwrap: 3.0-
+this: 3.0-
+threading: 3.0-
+time: 3.0-
+timeit: 3.0-
+tkinter: 3.0-
+token: 3.0-
+tokenize: 3.0-
+tomllib: 3.11-
+trace: 3.0-
+traceback: 3.0-
+tracemalloc: 3.4-
+tty: 3.0-
+turtle: 3.0-
+types: 3.0-
+typing: 3.5-
+typing_extensions: 3.0-
+unicodedata: 3.0-
+unittest: 3.0-
+unittest._log: 3.9-
+unittest.async_case: 3.8-
+urllib: 3.0-
+uu: 3.0-3.12
+uuid: 3.0-
+venv: 3.3-
+warnings: 3.0-
+wave: 3.0-
+weakref: 3.0-
+webbrowser: 3.0-
+winreg: 3.0-
+winsound: 3.0-
+wsgiref: 3.0-
+wsgiref.types: 3.11-
+xdrlib: 3.0-3.12
+xml: 3.0-
+xmlrpc: 3.0-
+xxlimited: 3.2-
+zipapp: 3.5-
+zipfile: 3.0-
+zipfile._path: 3.12-
+zipimport: 3.0-
+zlib: 3.0-
+zoneinfo: 3.9-

crates/red_knot/vendor/typeshed/stdlib/__future__.pyi

@@ -0,0 +1,36 @@
+from typing_extensions import TypeAlias
+
+_VersionInfo: TypeAlias = tuple[int, int, int, str, int]
+
+class _Feature:
+    def __init__(self, optionalRelease: _VersionInfo, mandatoryRelease: _VersionInfo | None, compiler_flag: int) -> None: ...
+    def getOptionalRelease(self) -> _VersionInfo: ...
+    def getMandatoryRelease(self) -> _VersionInfo | None: ...
+    compiler_flag: int
+
+absolute_import: _Feature
+division: _Feature
+generators: _Feature
+nested_scopes: _Feature
+print_function: _Feature
+unicode_literals: _Feature
+with_statement: _Feature
+barry_as_FLUFL: _Feature
+generator_stop: _Feature
+annotations: _Feature
+
+all_feature_names: list[str]  # undocumented
+
+__all__ = [
+    "all_feature_names",
+    "absolute_import",
+    "division",
+    "generators",
+    "nested_scopes",
+    "print_function",
+    "unicode_literals",
+    "with_statement",
+    "barry_as_FLUFL",
+    "generator_stop",
+    "annotations",
+]

crates/red_knot/vendor/typeshed/stdlib/__main__.pyi

@@ -0,0 +1,3 @@
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...

crates/red_knot/vendor/typeshed/stdlib/_bisect.pyi

@@ -0,0 +1,84 @@
+import sys
+from _typeshed import SupportsLenAndGetItem, SupportsRichComparisonT
+from collections.abc import Callable, MutableSequence
+from typing import TypeVar, overload
+
+_T = TypeVar("_T")
+
+if sys.version_info >= (3, 10):
+    @overload
+    def bisect_left(
+        a: SupportsLenAndGetItem[SupportsRichComparisonT],
+        x: SupportsRichComparisonT,
+        lo: int = 0,
+        hi: int | None = None,
+        *,
+        key: None = None,
+    ) -> int: ...
+    @overload
+    def bisect_left(
+        a: SupportsLenAndGetItem[_T],
+        x: SupportsRichComparisonT,
+        lo: int = 0,
+        hi: int | None = None,
+        *,
+        key: Callable[[_T], SupportsRichComparisonT],
+    ) -> int: ...
+    @overload
+    def bisect_right(
+        a: SupportsLenAndGetItem[SupportsRichComparisonT],
+        x: SupportsRichComparisonT,
+        lo: int = 0,
+        hi: int | None = None,
+        *,
+        key: None = None,
+    ) -> int: ...
+    @overload
+    def bisect_right(
+        a: SupportsLenAndGetItem[_T],
+        x: SupportsRichComparisonT,
+        lo: int = 0,
+        hi: int | None = None,
+        *,
+        key: Callable[[_T], SupportsRichComparisonT],
+    ) -> int: ...
+    @overload
+    def insort_left(
+        a: MutableSequence[SupportsRichComparisonT],
+        x: SupportsRichComparisonT,
+        lo: int = 0,
+        hi: int | None = None,
+        *,
+        key: None = None,
+    ) -> None: ...
+    @overload
+    def insort_left(
+        a: MutableSequence[_T], x: _T, lo: int = 0, hi: int | None = None, *, key: Callable[[_T], SupportsRichComparisonT]
+    ) -> None: ...
+    @overload
+    def insort_right(
+        a: MutableSequence[SupportsRichComparisonT],
+        x: SupportsRichComparisonT,
+        lo: int = 0,
+        hi: int | None = None,
+        *,
+        key: None = None,
+    ) -> None: ...
+    @overload
+    def insort_right(
+        a: MutableSequence[_T], x: _T, lo: int = 0, hi: int | None = None, *, key: Callable[[_T], SupportsRichComparisonT]
+    ) -> None: ...
+
+else:
+    def bisect_left(
+        a: SupportsLenAndGetItem[SupportsRichComparisonT], x: SupportsRichComparisonT, lo: int = 0, hi: int | None = None
+    ) -> int: ...
+    def bisect_right(
+        a: SupportsLenAndGetItem[SupportsRichComparisonT], x: SupportsRichComparisonT, lo: int = 0, hi: int | None = None
+    ) -> int: ...
+    def insort_left(
+        a: MutableSequence[SupportsRichComparisonT], x: SupportsRichComparisonT, lo: int = 0, hi: int | None = None
+    ) -> None: ...
+    def insort_right(
+        a: MutableSequence[SupportsRichComparisonT], x: SupportsRichComparisonT, lo: int = 0, hi: int | None = None
+    ) -> None: ...

crates/red_knot/vendor/typeshed/stdlib/_bootlocale.pyi

@@ -0,0 +1 @@
+def getpreferredencoding(do_setlocale: bool = True) -> str: ...

crates/red_knot/vendor/typeshed/stdlib/_codecs.pyi

@@ -0,0 +1,133 @@
+import codecs
+import sys
+from _typeshed import ReadableBuffer
+from collections.abc import Callable
+from typing import Literal, overload
+from typing_extensions import TypeAlias
+
+# This type is not exposed; it is defined in unicodeobject.c
+class _EncodingMap:
+    def size(self) -> int: ...
+
+_CharMap: TypeAlias = dict[int, int] | _EncodingMap
+_Handler: TypeAlias = Callable[[UnicodeError], tuple[str | bytes, int]]
+_SearchFunction: TypeAlias = Callable[[str], codecs.CodecInfo | None]
+
+def register(search_function: _SearchFunction, /) -> None: ...
+
+if sys.version_info >= (3, 10):
+    def unregister(search_function: _SearchFunction, /) -> None: ...
+
+def register_error(errors: str, handler: _Handler, /) -> None: ...
+def lookup_error(name: str, /) -> _Handler: ...
+
+# The type ignore on `encode` and `decode` is to avoid issues with overlapping overloads, for more details, see #300
+# https://docs.python.org/3/library/codecs.html#binary-transforms
+_BytesToBytesEncoding: TypeAlias = Literal[
+    "base64",
+    "base_64",
+    "base64_codec",
+    "bz2",
+    "bz2_codec",
+    "hex",
+    "hex_codec",
+    "quopri",
+    "quotedprintable",
+    "quoted_printable",
+    "quopri_codec",
+    "uu",
+    "uu_codec",
+    "zip",
+    "zlib",
+    "zlib_codec",
+]
+# https://docs.python.org/3/library/codecs.html#text-transforms
+_StrToStrEncoding: TypeAlias = Literal["rot13", "rot_13"]
+
+@overload
+def encode(obj: ReadableBuffer, encoding: _BytesToBytesEncoding, errors: str = "strict") -> bytes: ...
+@overload
+def encode(obj: str, encoding: _StrToStrEncoding, errors: str = "strict") -> str: ...  # type: ignore[overload-overlap]
+@overload
+def encode(obj: str, encoding: str = "utf-8", errors: str = "strict") -> bytes: ...
+@overload
+def decode(obj: ReadableBuffer, encoding: _BytesToBytesEncoding, errors: str = "strict") -> bytes: ...  # type: ignore[overload-overlap]
+@overload
+def decode(obj: str, encoding: _StrToStrEncoding, errors: str = "strict") -> str: ...
+
+# these are documented as text encodings but in practice they also accept str as input
+@overload
+def decode(
+    obj: str,
+    encoding: Literal["unicode_escape", "unicode-escape", "raw_unicode_escape", "raw-unicode-escape"],
+    errors: str = "strict",
+) -> str: ...
+
+# hex is officially documented as a bytes to bytes encoding, but it appears to also work with str
+@overload
+def decode(obj: str, encoding: Literal["hex", "hex_codec"], errors: str = "strict") -> bytes: ...
+@overload
+def decode(obj: ReadableBuffer, encoding: str = "utf-8", errors: str = "strict") -> str: ...
+def lookup(encoding: str, /) -> codecs.CodecInfo: ...
+def charmap_build(map: str, /) -> _CharMap: ...
+def ascii_decode(data: ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
+def ascii_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+def charmap_decode(data: ReadableBuffer, errors: str | None = None, mapping: _CharMap | None = None, /) -> tuple[str, int]: ...
+def charmap_encode(str: str, errors: str | None = None, mapping: _CharMap | None = None, /) -> tuple[bytes, int]: ...
+def escape_decode(data: str | ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
+def escape_encode(data: bytes, errors: str | None = None, /) -> tuple[bytes, int]: ...
+def latin_1_decode(data: ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
+def latin_1_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+
+if sys.version_info >= (3, 9):
+    def raw_unicode_escape_decode(
+        data: str | ReadableBuffer, errors: str | None = None, final: bool = True, /
+    ) -> tuple[str, int]: ...
+
+else:
+    def raw_unicode_escape_decode(data: str | ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
+
+def raw_unicode_escape_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+def readbuffer_encode(data: str | ReadableBuffer, errors: str | None = None, /) -> tuple[bytes, int]: ...
+
+if sys.version_info >= (3, 9):
+    def unicode_escape_decode(
+        data: str | ReadableBuffer, errors: str | None = None, final: bool = True, /
+    ) -> tuple[str, int]: ...
+
+else:
+    def unicode_escape_decode(data: str | ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
+
+def unicode_escape_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+def utf_16_be_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
+def utf_16_be_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+def utf_16_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
+def utf_16_encode(str: str, errors: str | None = None, byteorder: int = 0, /) -> tuple[bytes, int]: ...
+def utf_16_ex_decode(
+    data: ReadableBuffer, errors: str | None = None, byteorder: int = 0, final: bool = False, /
+) -> tuple[str, int, int]: ...
+def utf_16_le_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
+def utf_16_le_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+def utf_32_be_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
+def utf_32_be_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+def utf_32_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
+def utf_32_encode(str: str, errors: str | None = None, byteorder: int = 0, /) -> tuple[bytes, int]: ...
+def utf_32_ex_decode(
+    data: ReadableBuffer, errors: str | None = None, byteorder: int = 0, final: bool = False, /
+) -> tuple[str, int, int]: ...
+def utf_32_le_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
+def utf_32_le_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+def utf_7_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
+def utf_7_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+def utf_8_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
+def utf_8_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+
+if sys.platform == "win32":
+    def mbcs_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
+    def mbcs_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+    def code_page_decode(
+        codepage: int, data: ReadableBuffer, errors: str | None = None, final: bool = False, /
+    ) -> tuple[str, int]: ...
+    def code_page_encode(code_page: int, str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+    def oem_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
+    def oem_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...

crates/red_knot/vendor/typeshed/stdlib/_collections_abc.pyi

@@ -0,0 +1,94 @@
+import sys
+from abc import abstractmethod
+from types import MappingProxyType
+from typing import (  # noqa: Y022,Y038,Y057
+    AbstractSet as Set,
+    AsyncGenerator as AsyncGenerator,
+    AsyncIterable as AsyncIterable,
+    AsyncIterator as AsyncIterator,
+    Awaitable as Awaitable,
+    ByteString as ByteString,
+    Callable as Callable,
+    Collection as Collection,
+    Container as Container,
+    Coroutine as Coroutine,
+    Generator as Generator,
+    Generic,
+    Hashable as Hashable,
+    ItemsView as ItemsView,
+    Iterable as Iterable,
+    Iterator as Iterator,
+    KeysView as KeysView,
+    Mapping as Mapping,
+    MappingView as MappingView,
+    MutableMapping as MutableMapping,
+    MutableSequence as MutableSequence,
+    MutableSet as MutableSet,
+    Protocol,
+    Reversible as Reversible,
+    Sequence as Sequence,
+    Sized as Sized,
+    TypeVar,
+    ValuesView as ValuesView,
+    final,
+    runtime_checkable,
+)
+
+__all__ = [
+    "Awaitable",
+    "Coroutine",
+    "AsyncIterable",
+    "AsyncIterator",
+    "AsyncGenerator",
+    "Hashable",
+    "Iterable",
+    "Iterator",
+    "Generator",
+    "Reversible",
+    "Sized",
+    "Container",
+    "Callable",
+    "Collection",
+    "Set",
+    "MutableSet",
+    "Mapping",
+    "MutableMapping",
+    "MappingView",
+    "KeysView",
+    "ItemsView",
+    "ValuesView",
+    "Sequence",
+    "MutableSequence",
+    "ByteString",
+]
+if sys.version_info >= (3, 12):
+    __all__ += ["Buffer"]
+
+_KT_co = TypeVar("_KT_co", covariant=True)  # Key type covariant containers.
+_VT_co = TypeVar("_VT_co", covariant=True)  # Value type covariant containers.
+
+@final
+class dict_keys(KeysView[_KT_co], Generic[_KT_co, _VT_co]):  # undocumented
+    def __eq__(self, value: object, /) -> bool: ...
+    if sys.version_info >= (3, 10):
+        @property
+        def mapping(self) -> MappingProxyType[_KT_co, _VT_co]: ...
+
+@final
+class dict_values(ValuesView[_VT_co], Generic[_KT_co, _VT_co]):  # undocumented
+    if sys.version_info >= (3, 10):
+        @property
+        def mapping(self) -> MappingProxyType[_KT_co, _VT_co]: ...
+
+@final
+class dict_items(ItemsView[_KT_co, _VT_co]):  # undocumented
+    def __eq__(self, value: object, /) -> bool: ...
+    if sys.version_info >= (3, 10):
+        @property
+        def mapping(self) -> MappingProxyType[_KT_co, _VT_co]: ...
+
+if sys.version_info >= (3, 12):
+    @runtime_checkable
+    class Buffer(Protocol):
+        @abstractmethod
+        def __buffer__(self, flags: int, /) -> memoryview: ...

crates/red_knot/vendor/typeshed/stdlib/_compat_pickle.pyi

@@ -0,0 +1,8 @@
+IMPORT_MAPPING: dict[str, str]
+NAME_MAPPING: dict[tuple[str, str], tuple[str, str]]
+PYTHON2_EXCEPTIONS: tuple[str, ...]
+MULTIPROCESSING_EXCEPTIONS: tuple[str, ...]
+REVERSE_IMPORT_MAPPING: dict[str, str]
+REVERSE_NAME_MAPPING: dict[tuple[str, str], tuple[str, str]]
+PYTHON3_OSERROR_EXCEPTIONS: tuple[str, ...]
+PYTHON3_IMPORTERROR_EXCEPTIONS: tuple[str, ...]

crates/red_knot/vendor/typeshed/stdlib/_compression.pyi

@@ -0,0 +1,25 @@
+from _typeshed import WriteableBuffer
+from collections.abc import Callable
+from io import DEFAULT_BUFFER_SIZE, BufferedIOBase, RawIOBase
+from typing import Any, Protocol
+
+BUFFER_SIZE = DEFAULT_BUFFER_SIZE
+
+class _Reader(Protocol):
+    def read(self, n: int, /) -> bytes: ...
+    def seekable(self) -> bool: ...
+    def seek(self, n: int, /) -> Any: ...
+
+class BaseStream(BufferedIOBase): ...
+
+class DecompressReader(RawIOBase):
+    def __init__(
+        self,
+        fp: _Reader,
+        decomp_factory: Callable[..., object],
+        trailing_error: type[Exception] | tuple[type[Exception], ...] = (),
+        **decomp_args: Any,
+    ) -> None: ...
+    def readinto(self, b: WriteableBuffer) -> int: ...
+    def read(self, size: int = -1) -> bytes: ...
+    def seek(self, offset: int, whence: int = 0) -> int: ...

crates/red_knot/vendor/typeshed/stdlib/_csv.pyi

@@ -0,0 +1,90 @@
+import sys
+from _typeshed import SupportsWrite
+from collections.abc import Iterable, Iterator
+from typing import Any, Final, Literal
+from typing_extensions import TypeAlias
+
+__version__: Final[str]
+
+QUOTE_ALL: Literal[1]
+QUOTE_MINIMAL: Literal[0]
+QUOTE_NONE: Literal[3]
+QUOTE_NONNUMERIC: Literal[2]
+if sys.version_info >= (3, 12):
+    QUOTE_STRINGS: Literal[4]
+    QUOTE_NOTNULL: Literal[5]
+
+# Ideally this would be `QUOTE_ALL | QUOTE_MINIMAL | QUOTE_NONE | QUOTE_NONNUMERIC`
+# However, using literals in situations like these can cause false-positives (see #7258)
+_QuotingType: TypeAlias = int
+
+class Error(Exception): ...
+
+class Dialect:
+    delimiter: str
+    quotechar: str | None
+    escapechar: str | None
+    doublequote: bool
+    skipinitialspace: bool
+    lineterminator: str
+    quoting: _QuotingType
+    strict: bool
+    def __init__(self) -> None: ...
+
+_DialectLike: TypeAlias = str | Dialect | type[Dialect]
+
+class _reader(Iterator[list[str]]):
+    @property
+    def dialect(self) -> Dialect: ...
+    line_num: int
+    def __next__(self) -> list[str]: ...
+
+class _writer:
+    @property
+    def dialect(self) -> Dialect: ...
+    def writerow(self, row: Iterable[Any]) -> Any: ...
+    def writerows(self, rows: Iterable[Iterable[Any]]) -> None: ...
+
+def writer(
+    csvfile: SupportsWrite[str],
+    dialect: _DialectLike = "excel",
+    *,
+    delimiter: str = ",",
+    quotechar: str | None = '"',
+    escapechar: str | None = None,
+    doublequote: bool = True,
+    skipinitialspace: bool = False,
+    lineterminator: str = "\r\n",
+    quoting: _QuotingType = 0,
+    strict: bool = False,
+) -> _writer: ...
+def reader(
+    csvfile: Iterable[str],
+    dialect: _DialectLike = "excel",
+    *,
+    delimiter: str = ",",
+    quotechar: str | None = '"',
+    escapechar: str | None = None,
+    doublequote: bool = True,
+    skipinitialspace: bool = False,
+    lineterminator: str = "\r\n",
+    quoting: _QuotingType = 0,
+    strict: bool = False,
+) -> _reader: ...
+def register_dialect(
+    name: str,
+    dialect: type[Dialect] = ...,
+    *,
+    delimiter: str = ",",
+    quotechar: str | None = '"',
+    escapechar: str | None = None,
+    doublequote: bool = True,
+    skipinitialspace: bool = False,
+    lineterminator: str = "\r\n",
+    quoting: _QuotingType = 0,
+    strict: bool = False,
+) -> None: ...
+def unregister_dialect(name: str) -> None: ...
+def get_dialect(name: str) -> Dialect: ...
+def list_dialects() -> list[str]: ...
+def field_size_limit(new_limit: int = ...) -> int: ...

crates/red_knot/vendor/typeshed/stdlib/_ctypes.pyi

@@ -0,0 +1,211 @@
+import sys
+from _typeshed import ReadableBuffer, WriteableBuffer
+from abc import abstractmethod
+from collections.abc import Callable, Iterable, Iterator, Mapping, Sequence
+from ctypes import CDLL, ArgumentError as ArgumentError
+from typing import Any, ClassVar, Generic, TypeVar, overload
+from typing_extensions import Self, TypeAlias
+
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
+_T = TypeVar("_T")
+_CT = TypeVar("_CT", bound=_CData)
+
+FUNCFLAG_CDECL: int
+FUNCFLAG_PYTHONAPI: int
+FUNCFLAG_USE_ERRNO: int
+FUNCFLAG_USE_LASTERROR: int
+RTLD_GLOBAL: int
+RTLD_LOCAL: int
+
+if sys.version_info >= (3, 11):
+    CTYPES_MAX_ARGCOUNT: int
+
+if sys.version_info >= (3, 12):
+    SIZEOF_TIME_T: int
+
+if sys.platform == "win32":
+    # Description, Source, HelpFile, HelpContext, scode
+    _COMError_Details: TypeAlias = tuple[str | None, str | None, str | None, int | None, int | None]
+
+    class COMError(Exception):
+        hresult: int
+        text: str | None
+        details: _COMError_Details
+
+        def __init__(self, hresult: int, text: str | None, details: _COMError_Details) -> None: ...
+
+    def CopyComPointer(src: _PointerLike, dst: _PointerLike | _CArgObject) -> int: ...
+
+    FUNCFLAG_HRESULT: int
+    FUNCFLAG_STDCALL: int
+
+    def FormatError(code: int = ...) -> str: ...
+    def get_last_error() -> int: ...
+    def set_last_error(value: int) -> int: ...
+    def LoadLibrary(name: str, load_flags: int = 0, /) -> int: ...
+    def FreeLibrary(handle: int, /) -> None: ...
+
+class _CDataMeta(type):
+    # By default mypy complains about the following two methods, because strictly speaking cls
+    # might not be a Type[_CT]. However this can never actually happen, because the only class that
+    # uses _CDataMeta as its metaclass is _CData. So it's safe to ignore the errors here.
+    def __mul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc]
+    def __rmul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc]
+
+class _CData(metaclass=_CDataMeta):
+    _b_base_: int
+    _b_needsfree_: bool
+    _objects: Mapping[Any, int] | None
+    # At runtime the following classmethods are available only on classes, not
+    # on instances. This can't be reflected properly in the type system:
+    #
+    # Structure.from_buffer(...)  # valid at runtime
+    # Structure(...).from_buffer(...)  # invalid at runtime
+    #
+
+    @classmethod
+    def from_buffer(cls, source: WriteableBuffer, offset: int = ...) -> Self: ...
+    @classmethod
+    def from_buffer_copy(cls, source: ReadableBuffer, offset: int = ...) -> Self: ...
+    @classmethod
+    def from_address(cls, address: int) -> Self: ...
+    @classmethod
+    def from_param(cls, obj: Any) -> Self | _CArgObject: ...
+    @classmethod
+    def in_dll(cls, library: CDLL, name: str) -> Self: ...
+    def __buffer__(self, flags: int, /) -> memoryview: ...
+    def __release_buffer__(self, buffer: memoryview, /) -> None: ...
+
+class _SimpleCData(_CData, Generic[_T]):
+    value: _T
+    # The TypeVar can be unsolved here,
+    # but we can't use overloads without creating many, many mypy false-positive errors
+    def __init__(self, value: _T = ...) -> None: ...  # pyright: ignore[reportInvalidTypeVarUse]
+
+class _CanCastTo(_CData): ...
+class _PointerLike(_CanCastTo): ...
+
+class _Pointer(_PointerLike, _CData, Generic[_CT]):
+    _type_: type[_CT]
+    contents: _CT
+    @overload
+    def __init__(self) -> None: ...
+    @overload
+    def __init__(self, arg: _CT) -> None: ...
+    @overload
+    def __getitem__(self, key: int, /) -> Any: ...
+    @overload
+    def __getitem__(self, key: slice, /) -> list[Any]: ...
+    def __setitem__(self, key: int, value: Any, /) -> None: ...
+
+def POINTER(type: type[_CT]) -> type[_Pointer[_CT]]: ...
+def pointer(arg: _CT, /) -> _Pointer[_CT]: ...
+
+class _CArgObject: ...
+
+def byref(obj: _CData, offset: int = ...) -> _CArgObject: ...
+
+_ECT: TypeAlias = Callable[[_CData | None, CFuncPtr, tuple[_CData, ...]], _CData]
+_PF: TypeAlias = tuple[int] | tuple[int, str | None] | tuple[int, str | None, Any]
+
+class CFuncPtr(_PointerLike, _CData):
+    restype: type[_CData] | Callable[[int], Any] | None
+    argtypes: Sequence[type[_CData]]
+    errcheck: _ECT
+    # Abstract attribute that must be defined on subclasses
+    _flags_: ClassVar[int]
+    @overload
+    def __init__(self) -> None: ...
+    @overload
+    def __init__(self, address: int, /) -> None: ...
+    @overload
+    def __init__(self, callable: Callable[..., Any], /) -> None: ...
+    @overload
+    def __init__(self, func_spec: tuple[str | int, CDLL], paramflags: tuple[_PF, ...] | None = ..., /) -> None: ...
+    if sys.platform == "win32":
+        @overload
+        def __init__(
+            self, vtbl_index: int, name: str, paramflags: tuple[_PF, ...] | None = ..., iid: _CData | None = ..., /
+        ) -> None: ...
+
+    def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
+
+_GetT = TypeVar("_GetT")
+_SetT = TypeVar("_SetT")
+
+class _CField(Generic[_CT, _GetT, _SetT]):
+    offset: int
+    size: int
+    @overload
+    def __get__(self, instance: None, owner: type[Any] | None, /) -> Self: ...
+    @overload
+    def __get__(self, instance: Any, owner: type[Any] | None, /) -> _GetT: ...
+    def __set__(self, instance: Any, value: _SetT, /) -> None: ...
+
+class _StructUnionMeta(_CDataMeta):
+    _fields_: Sequence[tuple[str, type[_CData]] | tuple[str, type[_CData], int]]
+    _pack_: int
+    _anonymous_: Sequence[str]
+    def __getattr__(self, name: str) -> _CField[Any, Any, Any]: ...
+
+class _StructUnionBase(_CData, metaclass=_StructUnionMeta):
+    def __init__(self, *args: Any, **kw: Any) -> None: ...
+    def __getattr__(self, name: str) -> Any: ...
+    def __setattr__(self, name: str, value: Any) -> None: ...
+
+class Union(_StructUnionBase): ...
+class Structure(_StructUnionBase): ...
+
+class Array(_CData, Generic[_CT]):
+    @property
+    @abstractmethod
+    def _length_(self) -> int: ...
+    @_length_.setter
+    def _length_(self, value: int) -> None: ...
+    @property
+    @abstractmethod
+    def _type_(self) -> type[_CT]: ...
+    @_type_.setter
+    def _type_(self, value: type[_CT]) -> None: ...
+    # Note: only available if _CT == c_char
+    @property
+    def raw(self) -> bytes: ...
+    @raw.setter
+    def raw(self, value: ReadableBuffer) -> None: ...
+    value: Any  # Note: bytes if _CT == c_char, str if _CT == c_wchar, unavailable otherwise
+    # TODO These methods cannot be annotated correctly at the moment.
+    # All of these "Any"s stand for the array's element type, but it's not possible to use _CT
+    # here, because of a special feature of ctypes.
+    # By default, when accessing an element of an Array[_CT], the returned object has type _CT.
+    # However, when _CT is a "simple type" like c_int, ctypes automatically "unboxes" the object
+    # and converts it to the corresponding Python primitive. For example, when accessing an element
+    # of an Array[c_int], a Python int object is returned, not a c_int.
+    # This behavior does *not* apply to subclasses of "simple types".
+    # If MyInt is a subclass of c_int, then accessing an element of an Array[MyInt] returns
+    # a MyInt, not an int.
+    # This special behavior is not easy to model in a stub, so for now all places where
+    # the array element type would belong are annotated with Any instead.
+    def __init__(self, *args: Any) -> None: ...
+    @overload
+    def __getitem__(self, key: int, /) -> Any: ...
+    @overload
+    def __getitem__(self, key: slice, /) -> list[Any]: ...
+    @overload
+    def __setitem__(self, key: int, value: Any, /) -> None: ...
+    @overload
+    def __setitem__(self, key: slice, value: Iterable[Any], /) -> None: ...
+    def __iter__(self) -> Iterator[Any]: ...
+    # Can't inherit from Sized because the metaclass conflict between
+    # Sized and _CData prevents using _CDataMeta.
+    def __len__(self) -> int: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
+
+def addressof(obj: _CData) -> int: ...
+def alignment(obj_or_type: _CData | type[_CData]) -> int: ...
+def get_errno() -> int: ...
+def resize(obj: _CData, size: int) -> None: ...
+def set_errno(value: int) -> int: ...
+def sizeof(obj_or_type: _CData | type[_CData]) -> int: ...

crates/red_knot/vendor/typeshed/stdlib/_curses.pyi

@@ -0,0 +1,566 @@
+import sys
+from _typeshed import ReadOnlyBuffer, SupportsRead
+from typing import IO, Any, NamedTuple, final, overload
+from typing_extensions import TypeAlias
+
+# NOTE: This module is ordinarily only available on Unix, but the windows-curses
+# package makes it available on Windows as well with the same contents.
+
+# Handled by PyCurses_ConvertToChtype in _cursesmodule.c.
+_ChType: TypeAlias = str | bytes | int
+
+# ACS codes are only initialized after initscr is called
+ACS_BBSS: int
+ACS_BLOCK: int
+ACS_BOARD: int
+ACS_BSBS: int
+ACS_BSSB: int
+ACS_BSSS: int
+ACS_BTEE: int
+ACS_BULLET: int
+ACS_CKBOARD: int
+ACS_DARROW: int
+ACS_DEGREE: int
+ACS_DIAMOND: int
+ACS_GEQUAL: int
+ACS_HLINE: int
+ACS_LANTERN: int
+ACS_LARROW: int
+ACS_LEQUAL: int
+ACS_LLCORNER: int
+ACS_LRCORNER: int
+ACS_LTEE: int
+ACS_NEQUAL: int
+ACS_PI: int
+ACS_PLMINUS: int
+ACS_PLUS: int
+ACS_RARROW: int
+ACS_RTEE: int
+ACS_S1: int
+ACS_S3: int
+ACS_S7: int
+ACS_S9: int
+ACS_SBBS: int
+ACS_SBSB: int
+ACS_SBSS: int
+ACS_SSBB: int
+ACS_SSBS: int
+ACS_SSSB: int
+ACS_SSSS: int
+ACS_STERLING: int
+ACS_TTEE: int
+ACS_UARROW: int
+ACS_ULCORNER: int
+ACS_URCORNER: int
+ACS_VLINE: int
+ALL_MOUSE_EVENTS: int
+A_ALTCHARSET: int
+A_ATTRIBUTES: int
+A_BLINK: int
+A_BOLD: int
+A_CHARTEXT: int
+A_COLOR: int
+A_DIM: int
+A_HORIZONTAL: int
+A_INVIS: int
+if sys.platform != "darwin":
+    A_ITALIC: int
+A_LEFT: int
+A_LOW: int
+A_NORMAL: int
+A_PROTECT: int
+A_REVERSE: int
+A_RIGHT: int
+A_STANDOUT: int
+A_TOP: int
+A_UNDERLINE: int
+A_VERTICAL: int
+BUTTON1_CLICKED: int
+BUTTON1_DOUBLE_CLICKED: int
+BUTTON1_PRESSED: int
+BUTTON1_RELEASED: int
+BUTTON1_TRIPLE_CLICKED: int
+BUTTON2_CLICKED: int
+BUTTON2_DOUBLE_CLICKED: int
+BUTTON2_PRESSED: int
+BUTTON2_RELEASED: int
+BUTTON2_TRIPLE_CLICKED: int
+BUTTON3_CLICKED: int
+BUTTON3_DOUBLE_CLICKED: int
+BUTTON3_PRESSED: int
+BUTTON3_RELEASED: int
+BUTTON3_TRIPLE_CLICKED: int
+BUTTON4_CLICKED: int
+BUTTON4_DOUBLE_CLICKED: int
+BUTTON4_PRESSED: int
+BUTTON4_RELEASED: int
+BUTTON4_TRIPLE_CLICKED: int
+# Darwin ncurses doesn't provide BUTTON5_* constants
+if sys.version_info >= (3, 10) and sys.platform != "darwin":
+    BUTTON5_PRESSED: int
+    BUTTON5_RELEASED: int
+    BUTTON5_CLICKED: int
+    BUTTON5_DOUBLE_CLICKED: int
+    BUTTON5_TRIPLE_CLICKED: int
+BUTTON_ALT: int
+BUTTON_CTRL: int
+BUTTON_SHIFT: int
+COLOR_BLACK: int
+COLOR_BLUE: int
+COLOR_CYAN: int
+COLOR_GREEN: int
+COLOR_MAGENTA: int
+COLOR_RED: int
+COLOR_WHITE: int
+COLOR_YELLOW: int
+ERR: int
+KEY_A1: int
+KEY_A3: int
+KEY_B2: int
+KEY_BACKSPACE: int
+KEY_BEG: int
+KEY_BREAK: int
+KEY_BTAB: int
+KEY_C1: int
+KEY_C3: int
+KEY_CANCEL: int
+KEY_CATAB: int
+KEY_CLEAR: int
+KEY_CLOSE: int
+KEY_COMMAND: int
+KEY_COPY: int
+KEY_CREATE: int
+KEY_CTAB: int
+KEY_DC: int
+KEY_DL: int
+KEY_DOWN: int
+KEY_EIC: int
+KEY_END: int
+KEY_ENTER: int
+KEY_EOL: int
+KEY_EOS: int
+KEY_EXIT: int
+KEY_F0: int
+KEY_F1: int
+KEY_F10: int
+KEY_F11: int
+KEY_F12: int
+KEY_F13: int
+KEY_F14: int
+KEY_F15: int
+KEY_F16: int
+KEY_F17: int
+KEY_F18: int
+KEY_F19: int
+KEY_F2: int
+KEY_F20: int
+KEY_F21: int
+KEY_F22: int
+KEY_F23: int
+KEY_F24: int
+KEY_F25: int
+KEY_F26: int
+KEY_F27: int
+KEY_F28: int
+KEY_F29: int
+KEY_F3: int
+KEY_F30: int
+KEY_F31: int
+KEY_F32: int
+KEY_F33: int
+KEY_F34: int
+KEY_F35: int
+KEY_F36: int
+KEY_F37: int
+KEY_F38: int
+KEY_F39: int
+KEY_F4: int
+KEY_F40: int
+KEY_F41: int
+KEY_F42: int
+KEY_F43: int
+KEY_F44: int
+KEY_F45: int
+KEY_F46: int
+KEY_F47: int
+KEY_F48: int
+KEY_F49: int
+KEY_F5: int
+KEY_F50: int
+KEY_F51: int
+KEY_F52: int
+KEY_F53: int
+KEY_F54: int
+KEY_F55: int
+KEY_F56: int
+KEY_F57: int
+KEY_F58: int
+KEY_F59: int
+KEY_F6: int
+KEY_F60: int
+KEY_F61: int
+KEY_F62: int
+KEY_F63: int
+KEY_F7: int
+KEY_F8: int
+KEY_F9: int
+KEY_FIND: int
+KEY_HELP: int
+KEY_HOME: int
+KEY_IC: int
+KEY_IL: int
+KEY_LEFT: int
+KEY_LL: int
+KEY_MARK: int
+KEY_MAX: int
+KEY_MESSAGE: int
+KEY_MIN: int
+KEY_MOUSE: int
+KEY_MOVE: int
+KEY_NEXT: int
+KEY_NPAGE: int
+KEY_OPEN: int
+KEY_OPTIONS: int
+KEY_PPAGE: int
+KEY_PREVIOUS: int
+KEY_PRINT: int
+KEY_REDO: int
+KEY_REFERENCE: int
+KEY_REFRESH: int
+KEY_REPLACE: int
+KEY_RESET: int
+KEY_RESIZE: int
+KEY_RESTART: int
+KEY_RESUME: int
+KEY_RIGHT: int
+KEY_SAVE: int
+KEY_SBEG: int
+KEY_SCANCEL: int
+KEY_SCOMMAND: int
+KEY_SCOPY: int
+KEY_SCREATE: int
+KEY_SDC: int
+KEY_SDL: int
+KEY_SELECT: int
+KEY_SEND: int
+KEY_SEOL: int
+KEY_SEXIT: int
+KEY_SF: int
+KEY_SFIND: int
+KEY_SHELP: int
+KEY_SHOME: int
+KEY_SIC: int
+KEY_SLEFT: int
+KEY_SMESSAGE: int
+KEY_SMOVE: int
+KEY_SNEXT: int
+KEY_SOPTIONS: int
+KEY_SPREVIOUS: int
+KEY_SPRINT: int
+KEY_SR: int
+KEY_SREDO: int
+KEY_SREPLACE: int
+KEY_SRESET: int
+KEY_SRIGHT: int
+KEY_SRSUME: int
+KEY_SSAVE: int
+KEY_SSUSPEND: int
+KEY_STAB: int
+KEY_SUNDO: int
+KEY_SUSPEND: int
+KEY_UNDO: int
+KEY_UP: int
+OK: int
+REPORT_MOUSE_POSITION: int
+_C_API: Any
+version: bytes
+
+def baudrate() -> int: ...
+def beep() -> None: ...
+def can_change_color() -> bool: ...
+def cbreak(flag: bool = True, /) -> None: ...
+def color_content(color_number: int, /) -> tuple[int, int, int]: ...
+def color_pair(pair_number: int, /) -> int: ...
+def curs_set(visibility: int, /) -> int: ...
+def def_prog_mode() -> None: ...
+def def_shell_mode() -> None: ...
+def delay_output(ms: int, /) -> None: ...
+def doupdate() -> None: ...
+def echo(flag: bool = True, /) -> None: ...
+def endwin() -> None: ...
+def erasechar() -> bytes: ...
+def filter() -> None: ...
+def flash() -> None: ...
+def flushinp() -> None: ...
+
+if sys.version_info >= (3, 9):
+    def get_escdelay() -> int: ...
+    def get_tabsize() -> int: ...
+
+def getmouse() -> tuple[int, int, int, int, int]: ...
+def getsyx() -> tuple[int, int]: ...
+def getwin(file: SupportsRead[bytes], /) -> _CursesWindow: ...
+def halfdelay(tenths: int, /) -> None: ...
+def has_colors() -> bool: ...
+
+if sys.version_info >= (3, 10):
+    def has_extended_color_support() -> bool: ...
+
+def has_ic() -> bool: ...
+def has_il() -> bool: ...
+def has_key(key: int, /) -> bool: ...
+def init_color(color_number: int, r: int, g: int, b: int, /) -> None: ...
+def init_pair(pair_number: int, fg: int, bg: int, /) -> None: ...
+def initscr() -> _CursesWindow: ...
+def intrflush(flag: bool, /) -> None: ...
+def is_term_resized(nlines: int, ncols: int, /) -> bool: ...
+def isendwin() -> bool: ...
+def keyname(key: int, /) -> bytes: ...
+def killchar() -> bytes: ...
+def longname() -> bytes: ...
+def meta(yes: bool, /) -> None: ...
+def mouseinterval(interval: int, /) -> None: ...
+def mousemask(newmask: int, /) -> tuple[int, int]: ...
+def napms(ms: int, /) -> int: ...
+def newpad(nlines: int, ncols: int, /) -> _CursesWindow: ...
+def newwin(nlines: int, ncols: int, begin_y: int = ..., begin_x: int = ..., /) -> _CursesWindow: ...
+def nl(flag: bool = True, /) -> None: ...
+def nocbreak() -> None: ...
+def noecho() -> None: ...
+def nonl() -> None: ...
+def noqiflush() -> None: ...
+def noraw() -> None: ...
+def pair_content(pair_number: int, /) -> tuple[int, int]: ...
+def pair_number(attr: int, /) -> int: ...
+def putp(string: ReadOnlyBuffer, /) -> None: ...
+def qiflush(flag: bool = True, /) -> None: ...
+def raw(flag: bool = True, /) -> None: ...
+def reset_prog_mode() -> None: ...
+def reset_shell_mode() -> None: ...
+def resetty() -> None: ...
+def resize_term(nlines: int, ncols: int, /) -> None: ...
+def resizeterm(nlines: int, ncols: int, /) -> None: ...
+def savetty() -> None: ...
+
+if sys.version_info >= (3, 9):
+    def set_escdelay(ms: int, /) -> None: ...
+    def set_tabsize(size: int, /) -> None: ...
+
+def setsyx(y: int, x: int, /) -> None: ...
+def setupterm(term: str | None = None, fd: int = -1) -> None: ...
+def start_color() -> None: ...
+def termattrs() -> int: ...
+def termname() -> bytes: ...
+def tigetflag(capname: str, /) -> int: ...
+def tigetnum(capname: str, /) -> int: ...
+def tigetstr(capname: str, /) -> bytes | None: ...
+def tparm(
+    str: ReadOnlyBuffer,
+    i1: int = 0,
+    i2: int = 0,
+    i3: int = 0,
+    i4: int = 0,
+    i5: int = 0,
+    i6: int = 0,
+    i7: int = 0,
+    i8: int = 0,
+    i9: int = 0,
+    /,
+) -> bytes: ...
+def typeahead(fd: int, /) -> None: ...
+def unctrl(ch: _ChType, /) -> bytes: ...
+
+if sys.version_info < (3, 12) or sys.platform != "darwin":
+    # The support for macos was dropped in 3.12
+    def unget_wch(ch: int | str, /) -> None: ...
+
+def ungetch(ch: _ChType, /) -> None: ...
+def ungetmouse(id: int, x: int, y: int, z: int, bstate: int, /) -> None: ...
+def update_lines_cols() -> None: ...
+def use_default_colors() -> None: ...
+def use_env(flag: bool, /) -> None: ...
+
+class error(Exception): ...
+
+@final
+class _CursesWindow:
+    encoding: str
+    @overload
+    def addch(self, ch: _ChType, attr: int = ...) -> None: ...
+    @overload
+    def addch(self, y: int, x: int, ch: _ChType, attr: int = ...) -> None: ...
+    @overload
+    def addnstr(self, str: str, n: int, attr: int = ...) -> None: ...
+    @overload
+    def addnstr(self, y: int, x: int, str: str, n: int, attr: int = ...) -> None: ...
+    @overload
+    def addstr(self, str: str, attr: int = ...) -> None: ...
+    @overload
+    def addstr(self, y: int, x: int, str: str, attr: int = ...) -> None: ...
+    def attroff(self, attr: int, /) -> None: ...
+    def attron(self, attr: int, /) -> None: ...
+    def attrset(self, attr: int, /) -> None: ...
+    def bkgd(self, ch: _ChType, attr: int = ..., /) -> None: ...
+    def bkgdset(self, ch: _ChType, attr: int = ..., /) -> None: ...
+    def border(
+        self,
+        ls: _ChType = ...,
+        rs: _ChType = ...,
+        ts: _ChType = ...,
+        bs: _ChType = ...,
+        tl: _ChType = ...,
+        tr: _ChType = ...,
+        bl: _ChType = ...,
+        br: _ChType = ...,
+    ) -> None: ...
+    @overload
+    def box(self) -> None: ...
+    @overload
+    def box(self, vertch: _ChType = ..., horch: _ChType = ...) -> None: ...
+    @overload
+    def chgat(self, attr: int) -> None: ...
+    @overload
+    def chgat(self, num: int, attr: int) -> None: ...
+    @overload
+    def chgat(self, y: int, x: int, attr: int) -> None: ...
+    @overload
+    def chgat(self, y: int, x: int, num: int, attr: int) -> None: ...
+    def clear(self) -> None: ...
+    def clearok(self, yes: int) -> None: ...
+    def clrtobot(self) -> None: ...
+    def clrtoeol(self) -> None: ...
+    def cursyncup(self) -> None: ...
+    @overload
+    def delch(self) -> None: ...
+    @overload
+    def delch(self, y: int, x: int) -> None: ...
+    def deleteln(self) -> None: ...
+    @overload
+    def derwin(self, begin_y: int, begin_x: int) -> _CursesWindow: ...
+    @overload
+    def derwin(self, nlines: int, ncols: int, begin_y: int, begin_x: int) -> _CursesWindow: ...
+    def echochar(self, ch: _ChType, attr: int = ..., /) -> None: ...
+    def enclose(self, y: int, x: int, /) -> bool: ...
+    def erase(self) -> None: ...
+    def getbegyx(self) -> tuple[int, int]: ...
+    def getbkgd(self) -> tuple[int, int]: ...
+    @overload
+    def getch(self) -> int: ...
+    @overload
+    def getch(self, y: int, x: int) -> int: ...
+    if sys.version_info < (3, 12) or sys.platform != "darwin":
+        # The support for macos was dropped in 3.12
+        @overload
+        def get_wch(self) -> int | str: ...
+        @overload
+        def get_wch(self, y: int, x: int) -> int | str: ...
+
+    @overload
+    def getkey(self) -> str: ...
+    @overload
+    def getkey(self, y: int, x: int) -> str: ...
+    def getmaxyx(self) -> tuple[int, int]: ...
+    def getparyx(self) -> tuple[int, int]: ...
+    @overload
+    def getstr(self) -> bytes: ...
+    @overload
+    def getstr(self, n: int) -> bytes: ...
+    @overload
+    def getstr(self, y: int, x: int) -> bytes: ...
+    @overload
+    def getstr(self, y: int, x: int, n: int) -> bytes: ...
+    def getyx(self) -> tuple[int, int]: ...
+    @overload
+    def hline(self, ch: _ChType, n: int) -> None: ...
+    @overload
+    def hline(self, y: int, x: int, ch: _ChType, n: int) -> None: ...
+    def idcok(self, flag: bool) -> None: ...
+    def idlok(self, yes: bool) -> None: ...
+    def immedok(self, flag: bool) -> None: ...
+    @overload
+    def inch(self) -> int: ...
+    @overload
+    def inch(self, y: int, x: int) -> int: ...
+    @overload
+    def insch(self, ch: _ChType, attr: int = ...) -> None: ...
+    @overload
+    def insch(self, y: int, x: int, ch: _ChType, attr: int = ...) -> None: ...
+    def insdelln(self, nlines: int) -> None: ...
+    def insertln(self) -> None: ...
+    @overload
+    def insnstr(self, str: str, n: int, attr: int = ...) -> None: ...
+    @overload
+    def insnstr(self, y: int, x: int, str: str, n: int, attr: int = ...) -> None: ...
+    @overload
+    def insstr(self, str: str, attr: int = ...) -> None: ...
+    @overload
+    def insstr(self, y: int, x: int, str: str, attr: int = ...) -> None: ...
+    @overload
+    def instr(self, n: int = ...) -> bytes: ...
+    @overload
+    def instr(self, y: int, x: int, n: int = ...) -> bytes: ...
+    def is_linetouched(self, line: int, /) -> bool: ...
+    def is_wintouched(self) -> bool: ...
+    def keypad(self, yes: bool) -> None: ...
+    def leaveok(self, yes: bool) -> None: ...
+    def move(self, new_y: int, new_x: int) -> None: ...
+    def mvderwin(self, y: int, x: int) -> None: ...
+    def mvwin(self, new_y: int, new_x: int) -> None: ...
+    def nodelay(self, yes: bool) -> None: ...
+    def notimeout(self, yes: bool) -> None: ...
+    @overload
+    def noutrefresh(self) -> None: ...
+    @overload
+    def noutrefresh(self, pminrow: int, pmincol: int, sminrow: int, smincol: int, smaxrow: int, smaxcol: int) -> None: ...
+    @overload
+    def overlay(self, destwin: _CursesWindow) -> None: ...
+    @overload
+    def overlay(
+        self, destwin: _CursesWindow, sminrow: int, smincol: int, dminrow: int, dmincol: int, dmaxrow: int, dmaxcol: int
+    ) -> None: ...
+    @overload
+    def overwrite(self, destwin: _CursesWindow) -> None: ...
+    @overload
+    def overwrite(
+        self, destwin: _CursesWindow, sminrow: int, smincol: int, dminrow: int, dmincol: int, dmaxrow: int, dmaxcol: int
+    ) -> None: ...
+    def putwin(self, file: IO[Any], /) -> None: ...
+    def redrawln(self, beg: int, num: int, /) -> None: ...
+    def redrawwin(self) -> None: ...
+    @overload
+    def refresh(self) -> None: ...
+    @overload
+    def refresh(self, pminrow: int, pmincol: int, sminrow: int, smincol: int, smaxrow: int, smaxcol: int) -> None: ...
+    def resize(self, nlines: int, ncols: int) -> None: ...
+    def scroll(self, lines: int = ...) -> None: ...
+    def scrollok(self, flag: bool) -> None: ...
+    def setscrreg(self, top: int, bottom: int, /) -> None: ...
+    def standend(self) -> None: ...
+    def standout(self) -> None: ...
+    @overload
+    def subpad(self, begin_y: int, begin_x: int) -> _CursesWindow: ...
+    @overload
+    def subpad(self, nlines: int, ncols: int, begin_y: int, begin_x: int) -> _CursesWindow: ...
+    @overload
+    def subwin(self, begin_y: int, begin_x: int) -> _CursesWindow: ...
+    @overload
+    def subwin(self, nlines: int, ncols: int, begin_y: int, begin_x: int) -> _CursesWindow: ...
+    def syncdown(self) -> None: ...
+    def syncok(self, flag: bool) -> None: ...
+    def syncup(self) -> None: ...
+    def timeout(self, delay: int) -> None: ...
+    def touchline(self, start: int, count: int, changed: bool = ...) -> None: ...
+    def touchwin(self) -> None: ...
+    def untouchwin(self) -> None: ...
+    @overload
+    def vline(self, ch: _ChType, n: int) -> None: ...
+    @overload
+    def vline(self, y: int, x: int, ch: _ChType, n: int) -> None: ...
+
+class _ncurses_version(NamedTuple):
+    major: int
+    minor: int
+    patch: int
+
+ncurses_version: _ncurses_version
+window = _CursesWindow  # undocumented

crates/red_knot/vendor/typeshed/stdlib/_decimal.pyi

@@ -0,0 +1,281 @@
+import numbers
+import sys
+from collections.abc import Container, Sequence
+from types import TracebackType
+from typing import Any, ClassVar, Final, Literal, NamedTuple, overload
+from typing_extensions import Self, TypeAlias
+
+_Decimal: TypeAlias = Decimal | int
+_DecimalNew: TypeAlias = Decimal | float | str | tuple[int, Sequence[int], int]
+_ComparableNum: TypeAlias = Decimal | float | numbers.Rational
+
+__version__: Final[str]
+__libmpdec_version__: Final[str]
+
+class DecimalTuple(NamedTuple):
+    sign: int
+    digits: tuple[int, ...]
+    exponent: int | Literal["n", "N", "F"]
+
+ROUND_DOWN: str
+ROUND_HALF_UP: str
+ROUND_HALF_EVEN: str
+ROUND_CEILING: str
+ROUND_FLOOR: str
+ROUND_UP: str
+ROUND_HALF_DOWN: str
+ROUND_05UP: str
+HAVE_CONTEXTVAR: bool
+HAVE_THREADS: bool
+MAX_EMAX: int
+MAX_PREC: int
+MIN_EMIN: int
+MIN_ETINY: int
+
+class DecimalException(ArithmeticError): ...
+class Clamped(DecimalException): ...
+class InvalidOperation(DecimalException): ...
+class ConversionSyntax(InvalidOperation): ...
+class DivisionByZero(DecimalException, ZeroDivisionError): ...
+class DivisionImpossible(InvalidOperation): ...
+class DivisionUndefined(InvalidOperation, ZeroDivisionError): ...
+class Inexact(DecimalException): ...
+class InvalidContext(InvalidOperation): ...
+class Rounded(DecimalException): ...
+class Subnormal(DecimalException): ...
+class Overflow(Inexact, Rounded): ...
+class Underflow(Inexact, Rounded, Subnormal): ...
+class FloatOperation(DecimalException, TypeError): ...
+
+def setcontext(context: Context, /) -> None: ...
+def getcontext() -> Context: ...
+
+if sys.version_info >= (3, 11):
+    def localcontext(
+        ctx: Context | None = None,
+        *,
+        prec: int | None = ...,
+        rounding: str | None = ...,
+        Emin: int | None = ...,
+        Emax: int | None = ...,
+        capitals: int | None = ...,
+        clamp: int | None = ...,
+        traps: dict[_TrapType, bool] | None = ...,
+        flags: dict[_TrapType, bool] | None = ...,
+    ) -> _ContextManager: ...
+
+else:
+    def localcontext(ctx: Context | None = None) -> _ContextManager: ...
+
+class Decimal:
+    def __new__(cls, value: _DecimalNew = ..., context: Context | None = ...) -> Self: ...
+    @classmethod
+    def from_float(cls, f: float, /) -> Self: ...
+    def __bool__(self) -> bool: ...
+    def compare(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def __hash__(self) -> int: ...
+    def as_tuple(self) -> DecimalTuple: ...
+    def as_integer_ratio(self) -> tuple[int, int]: ...
+    def to_eng_string(self, context: Context | None = None) -> str: ...
+    def __abs__(self) -> Decimal: ...
+    def __add__(self, value: _Decimal, /) -> Decimal: ...
+    def __divmod__(self, value: _Decimal, /) -> tuple[Decimal, Decimal]: ...
+    def __eq__(self, value: object, /) -> bool: ...
+    def __floordiv__(self, value: _Decimal, /) -> Decimal: ...
+    def __ge__(self, value: _ComparableNum, /) -> bool: ...
+    def __gt__(self, value: _ComparableNum, /) -> bool: ...
+    def __le__(self, value: _ComparableNum, /) -> bool: ...
+    def __lt__(self, value: _ComparableNum, /) -> bool: ...
+    def __mod__(self, value: _Decimal, /) -> Decimal: ...
+    def __mul__(self, value: _Decimal, /) -> Decimal: ...
+    def __neg__(self) -> Decimal: ...
+    def __pos__(self) -> Decimal: ...
+    def __pow__(self, value: _Decimal, mod: _Decimal | None = None, /) -> Decimal: ...
+    def __radd__(self, value: _Decimal, /) -> Decimal: ...
+    def __rdivmod__(self, value: _Decimal, /) -> tuple[Decimal, Decimal]: ...
+    def __rfloordiv__(self, value: _Decimal, /) -> Decimal: ...
+    def __rmod__(self, value: _Decimal, /) -> Decimal: ...
+    def __rmul__(self, value: _Decimal, /) -> Decimal: ...
+    def __rsub__(self, value: _Decimal, /) -> Decimal: ...
+    def __rtruediv__(self, value: _Decimal, /) -> Decimal: ...
+    def __sub__(self, value: _Decimal, /) -> Decimal: ...
+    def __truediv__(self, value: _Decimal, /) -> Decimal: ...
+    def remainder_near(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def __float__(self) -> float: ...
+    def __int__(self) -> int: ...
+    def __trunc__(self) -> int: ...
+    @property
+    def real(self) -> Decimal: ...
+    @property
+    def imag(self) -> Decimal: ...
+    def conjugate(self) -> Decimal: ...
+    def __complex__(self) -> complex: ...
+    @overload
+    def __round__(self) -> int: ...
+    @overload
+    def __round__(self, ndigits: int, /) -> Decimal: ...
+    def __floor__(self) -> int: ...
+    def __ceil__(self) -> int: ...
+    def fma(self, other: _Decimal, third: _Decimal, context: Context | None = None) -> Decimal: ...
+    def __rpow__(self, value: _Decimal, mod: Context | None = None, /) -> Decimal: ...
+    def normalize(self, context: Context | None = None) -> Decimal: ...
+    def quantize(self, exp: _Decimal, rounding: str | None = None, context: Context | None = None) -> Decimal: ...
+    def same_quantum(self, other: _Decimal, context: Context | None = None) -> bool: ...
+    def to_integral_exact(self, rounding: str | None = None, context: Context | None = None) -> Decimal: ...
+    def to_integral_value(self, rounding: str | None = None, context: Context | None = None) -> Decimal: ...
+    def to_integral(self, rounding: str | None = None, context: Context | None = None) -> Decimal: ...
+    def sqrt(self, context: Context | None = None) -> Decimal: ...
+    def max(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def min(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def adjusted(self) -> int: ...
+    def canonical(self) -> Decimal: ...
+    def compare_signal(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def compare_total(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def compare_total_mag(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def copy_abs(self) -> Decimal: ...
+    def copy_negate(self) -> Decimal: ...
+    def copy_sign(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def exp(self, context: Context | None = None) -> Decimal: ...
+    def is_canonical(self) -> bool: ...
+    def is_finite(self) -> bool: ...
+    def is_infinite(self) -> bool: ...
+    def is_nan(self) -> bool: ...
+    def is_normal(self, context: Context | None = None) -> bool: ...
+    def is_qnan(self) -> bool: ...
+    def is_signed(self) -> bool: ...
+    def is_snan(self) -> bool: ...
+    def is_subnormal(self, context: Context | None = None) -> bool: ...
+    def is_zero(self) -> bool: ...
+    def ln(self, context: Context | None = None) -> Decimal: ...
+    def log10(self, context: Context | None = None) -> Decimal: ...
+    def logb(self, context: Context | None = None) -> Decimal: ...
+    def logical_and(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def logical_invert(self, context: Context | None = None) -> Decimal: ...
+    def logical_or(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def logical_xor(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def max_mag(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def min_mag(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def next_minus(self, context: Context | None = None) -> Decimal: ...
+    def next_plus(self, context: Context | None = None) -> Decimal: ...
+    def next_toward(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def number_class(self, context: Context | None = None) -> str: ...
+    def radix(self) -> Decimal: ...
+    def rotate(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def scaleb(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def shift(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
+    def __reduce__(self) -> tuple[type[Self], tuple[str]]: ...
+    def __copy__(self) -> Self: ...
+    def __deepcopy__(self, memo: Any, /) -> Self: ...
+    def __format__(self, specifier: str, context: Context | None = ..., /) -> str: ...
+
+class _ContextManager:
+    new_context: Context
+    saved_context: Context
+    def __init__(self, new_context: Context) -> None: ...
+    def __enter__(self) -> Context: ...
+    def __exit__(self, t: type[BaseException] | None, v: BaseException | None, tb: TracebackType | None) -> None: ...
+
+_TrapType: TypeAlias = type[DecimalException]
+
+class Context:
+    # TODO: Context doesn't allow you to delete *any* attributes from instances of the class at runtime,
+    # even settable attributes like `prec` and `rounding`,
+    # but that's inexpressable in the stub.
+    # Type checkers either ignore it or misinterpret it
+    # if you add a `def __delattr__(self, name: str, /) -> NoReturn` method to the stub
+    prec: int
+    rounding: str
+    Emin: int
+    Emax: int
+    capitals: int
+    clamp: int
+    traps: dict[_TrapType, bool]
+    flags: dict[_TrapType, bool]
+    def __init__(
+        self,
+        prec: int | None = ...,
+        rounding: str | None = ...,
+        Emin: int | None = ...,
+        Emax: int | None = ...,
+        capitals: int | None = ...,
+        clamp: int | None = ...,
+        flags: None | dict[_TrapType, bool] | Container[_TrapType] = ...,
+        traps: None | dict[_TrapType, bool] | Container[_TrapType] = ...,
+        _ignored_flags: list[_TrapType] | None = ...,
+    ) -> None: ...
+    def __reduce__(self) -> tuple[type[Self], tuple[Any, ...]]: ...
+    def clear_flags(self) -> None: ...
+    def clear_traps(self) -> None: ...
+    def copy(self) -> Context: ...
+    def __copy__(self) -> Context: ...
+    # see https://github.com/python/cpython/issues/94107
+    __hash__: ClassVar[None]  # type: ignore[assignment]
+    def Etiny(self) -> int: ...
+    def Etop(self) -> int: ...
+    def create_decimal(self, num: _DecimalNew = "0", /) -> Decimal: ...
+    def create_decimal_from_float(self, f: float, /) -> Decimal: ...
+    def abs(self, x: _Decimal, /) -> Decimal: ...
+    def add(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def canonical(self, x: Decimal, /) -> Decimal: ...
+    def compare(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def compare_signal(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def compare_total(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def compare_total_mag(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def copy_abs(self, x: _Decimal, /) -> Decimal: ...
+    def copy_decimal(self, x: _Decimal, /) -> Decimal: ...
+    def copy_negate(self, x: _Decimal, /) -> Decimal: ...
+    def copy_sign(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def divide(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def divide_int(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def divmod(self, x: _Decimal, y: _Decimal, /) -> tuple[Decimal, Decimal]: ...
+    def exp(self, x: _Decimal, /) -> Decimal: ...
+    def fma(self, x: _Decimal, y: _Decimal, z: _Decimal, /) -> Decimal: ...
+    def is_canonical(self, x: _Decimal, /) -> bool: ...
+    def is_finite(self, x: _Decimal, /) -> bool: ...
+    def is_infinite(self, x: _Decimal, /) -> bool: ...
+    def is_nan(self, x: _Decimal, /) -> bool: ...
+    def is_normal(self, x: _Decimal, /) -> bool: ...
+    def is_qnan(self, x: _Decimal, /) -> bool: ...
+    def is_signed(self, x: _Decimal, /) -> bool: ...
+    def is_snan(self, x: _Decimal, /) -> bool: ...
+    def is_subnormal(self, x: _Decimal, /) -> bool: ...
+    def is_zero(self, x: _Decimal, /) -> bool: ...
+    def ln(self, x: _Decimal, /) -> Decimal: ...
+    def log10(self, x: _Decimal, /) -> Decimal: ...
+    def logb(self, x: _Decimal, /) -> Decimal: ...
+    def logical_and(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def logical_invert(self, x: _Decimal, /) -> Decimal: ...
+    def logical_or(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def logical_xor(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def max(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def max_mag(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def min(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def min_mag(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def minus(self, x: _Decimal, /) -> Decimal: ...
+    def multiply(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def next_minus(self, x: _Decimal, /) -> Decimal: ...
+    def next_plus(self, x: _Decimal, /) -> Decimal: ...
+    def next_toward(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def normalize(self, x: _Decimal, /) -> Decimal: ...
+    def number_class(self, x: _Decimal, /) -> str: ...
+    def plus(self, x: _Decimal, /) -> Decimal: ...
+    def power(self, a: _Decimal, b: _Decimal, modulo: _Decimal | None = None) -> Decimal: ...
+    def quantize(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def radix(self) -> Decimal: ...
+    def remainder(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def remainder_near(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def rotate(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def same_quantum(self, x: _Decimal, y: _Decimal, /) -> bool: ...
+    def scaleb(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def shift(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def sqrt(self, x: _Decimal, /) -> Decimal: ...
+    def subtract(self, x: _Decimal, y: _Decimal, /) -> Decimal: ...
+    def to_eng_string(self, x: _Decimal, /) -> str: ...
+    def to_sci_string(self, x: _Decimal, /) -> str: ...
+    def to_integral_exact(self, x: _Decimal, /) -> Decimal: ...
+    def to_integral_value(self, x: _Decimal, /) -> Decimal: ...
+    def to_integral(self, x: _Decimal, /) -> Decimal: ...
+
+DefaultContext: Context
+BasicContext: Context
+ExtendedContext: Context

crates/red_knot/vendor/typeshed/stdlib/_dummy_thread.pyi

@@ -0,0 +1,33 @@
+from collections.abc import Callable
+from types import TracebackType
+from typing import Any, NoReturn, overload
+from typing_extensions import TypeVarTuple, Unpack
+
+__all__ = ["error", "start_new_thread", "exit", "get_ident", "allocate_lock", "interrupt_main", "LockType", "RLock"]
+
+_Ts = TypeVarTuple("_Ts")
+
+TIMEOUT_MAX: int
+error = RuntimeError
+
+@overload
+def start_new_thread(function: Callable[[Unpack[_Ts]], object], args: tuple[Unpack[_Ts]]) -> None: ...
+@overload
+def start_new_thread(function: Callable[..., object], args: tuple[Any, ...], kwargs: dict[str, Any]) -> None: ...
+def exit() -> NoReturn: ...
+def get_ident() -> int: ...
+def allocate_lock() -> LockType: ...
+def stack_size(size: int | None = None) -> int: ...
+
+class LockType:
+    locked_status: bool
+    def acquire(self, waitflag: bool | None = None, timeout: int = -1) -> bool: ...
+    def __enter__(self, waitflag: bool | None = None, timeout: int = -1) -> bool: ...
+    def __exit__(self, typ: type[BaseException] | None, val: BaseException | None, tb: TracebackType | None) -> None: ...
+    def release(self) -> bool: ...
+    def locked(self) -> bool: ...
+
+class RLock(LockType):
+    def release(self) -> None: ...  # type: ignore[override]
+
+def interrupt_main() -> None: ...

crates/red_knot/vendor/typeshed/stdlib/_dummy_threading.pyi

@@ -0,0 +1,164 @@
+import sys
+from _thread import _excepthook, _ExceptHookArgs
+from _typeshed import ProfileFunction, TraceFunction
+from collections.abc import Callable, Iterable, Mapping
+from types import TracebackType
+from typing import Any, TypeVar
+
+_T = TypeVar("_T")
+
+__all__ = [
+    "get_ident",
+    "active_count",
+    "Condition",
+    "current_thread",
+    "enumerate",
+    "main_thread",
+    "TIMEOUT_MAX",
+    "Event",
+    "Lock",
+    "RLock",
+    "Semaphore",
+    "BoundedSemaphore",
+    "Thread",
+    "Barrier",
+    "BrokenBarrierError",
+    "Timer",
+    "ThreadError",
+    "setprofile",
+    "settrace",
+    "local",
+    "stack_size",
+    "ExceptHookArgs",
+    "excepthook",
+]
+
+def active_count() -> int: ...
+def current_thread() -> Thread: ...
+def currentThread() -> Thread: ...
+def get_ident() -> int: ...
+def enumerate() -> list[Thread]: ...
+def main_thread() -> Thread: ...
+def settrace(func: TraceFunction) -> None: ...
+def setprofile(func: ProfileFunction | None) -> None: ...
+def stack_size(size: int | None = None) -> int: ...
+
+TIMEOUT_MAX: float
+
+class ThreadError(Exception): ...
+
+class local:
+    def __getattribute__(self, name: str) -> Any: ...
+    def __setattr__(self, name: str, value: Any) -> None: ...
+    def __delattr__(self, name: str) -> None: ...
+
+class Thread:
+    name: str
+    daemon: bool
+    @property
+    def ident(self) -> int | None: ...
+    def __init__(
+        self,
+        group: None = None,
+        target: Callable[..., object] | None = None,
+        name: str | None = None,
+        args: Iterable[Any] = (),
+        kwargs: Mapping[str, Any] | None = None,
+        *,
+        daemon: bool | None = None,
+    ) -> None: ...
+    def start(self) -> None: ...
+    def run(self) -> None: ...
+    def join(self, timeout: float | None = None) -> None: ...
+    def getName(self) -> str: ...
+    def setName(self, name: str) -> None: ...
+    @property
+    def native_id(self) -> int | None: ...  # only available on some platforms
+    def is_alive(self) -> bool: ...
+    if sys.version_info < (3, 9):
+        def isAlive(self) -> bool: ...
+
+    def isDaemon(self) -> bool: ...
+    def setDaemon(self, daemonic: bool) -> None: ...
+
+class _DummyThread(Thread): ...
+
+class Lock:
+    def __enter__(self) -> bool: ...
+    def __exit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
+    ) -> bool | None: ...
+    def acquire(self, blocking: bool = ..., timeout: float = ...) -> bool: ...
+    def release(self) -> None: ...
+    def locked(self) -> bool: ...
+
+class _RLock:
+    def __enter__(self) -> bool: ...
+    def __exit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
+    ) -> bool | None: ...
+    def acquire(self, blocking: bool = True, timeout: float = -1) -> bool: ...
+    def release(self) -> None: ...
+
+RLock = _RLock
+
+class Condition:
+    def __init__(self, lock: Lock | _RLock | None = None) -> None: ...
+    def __enter__(self) -> bool: ...
+    def __exit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
+    ) -> bool | None: ...
+    def acquire(self, blocking: bool = ..., timeout: float = ...) -> bool: ...
+    def release(self) -> None: ...
+    def wait(self, timeout: float | None = None) -> bool: ...
+    def wait_for(self, predicate: Callable[[], _T], timeout: float | None = None) -> _T: ...
+    def notify(self, n: int = 1) -> None: ...
+    def notify_all(self) -> None: ...
+    def notifyAll(self) -> None: ...
+
+class Semaphore:
+    def __init__(self, value: int = 1) -> None: ...
+    def __exit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
+    ) -> bool | None: ...
+    def acquire(self, blocking: bool = True, timeout: float | None = None) -> bool: ...
+    def __enter__(self, blocking: bool = True, timeout: float | None = None) -> bool: ...
+    if sys.version_info >= (3, 9):
+        def release(self, n: int = ...) -> None: ...
+    else:
+        def release(self) -> None: ...
+
+class BoundedSemaphore(Semaphore): ...
+
+class Event:
+    def is_set(self) -> bool: ...
+    def set(self) -> None: ...
+    def clear(self) -> None: ...
+    def wait(self, timeout: float | None = None) -> bool: ...
+
+excepthook = _excepthook
+ExceptHookArgs = _ExceptHookArgs
+
+class Timer(Thread):
+    def __init__(
+        self,
+        interval: float,
+        function: Callable[..., object],
+        args: Iterable[Any] | None = None,
+        kwargs: Mapping[str, Any] | None = None,
+    ) -> None: ...
+    def cancel(self) -> None: ...
+
+class Barrier:
+    @property
+    def parties(self) -> int: ...
+    @property
+    def n_waiting(self) -> int: ...
+    @property
+    def broken(self) -> bool: ...
+    def __init__(self, parties: int, action: Callable[[], None] | None = None, timeout: float | None = None) -> None: ...
+    def wait(self, timeout: float | None = None) -> int: ...
+    def reset(self) -> None: ...
+    def abort(self) -> None: ...
+
+class BrokenBarrierError(RuntimeError): ...

crates/red_knot/vendor/typeshed/stdlib/_heapq.pyi

@@ -0,0 +1,11 @@
+from typing import Any, Final, TypeVar
+
+_T = TypeVar("_T")
+
+__about__: Final[str]
+
+def heapify(heap: list[Any], /) -> None: ...
+def heappop(heap: list[_T], /) -> _T: ...
+def heappush(heap: list[_T], item: _T, /) -> None: ...
+def heappushpop(heap: list[_T], item: _T, /) -> _T: ...
+def heapreplace(heap: list[_T], item: _T, /) -> _T: ...

crates/red_knot/vendor/typeshed/stdlib/_imp.pyi

@@ -0,0 +1,28 @@
+import sys
+import types
+from _typeshed import ReadableBuffer
+from importlib.machinery import ModuleSpec
+from typing import Any
+
+check_hash_based_pycs: str
+
+def source_hash(key: int, source: ReadableBuffer) -> bytes: ...
+def create_builtin(spec: ModuleSpec, /) -> types.ModuleType: ...
+def create_dynamic(spec: ModuleSpec, file: Any = None, /) -> types.ModuleType: ...
+def acquire_lock() -> None: ...
+def exec_builtin(mod: types.ModuleType, /) -> int: ...
+def exec_dynamic(mod: types.ModuleType, /) -> int: ...
+def extension_suffixes() -> list[str]: ...
+def init_frozen(name: str, /) -> types.ModuleType: ...
+def is_builtin(name: str, /) -> int: ...
+def is_frozen(name: str, /) -> bool: ...
+def is_frozen_package(name: str, /) -> bool: ...
+def lock_held() -> bool: ...
+def release_lock() -> None: ...
+
+if sys.version_info >= (3, 11):
+    def find_frozen(name: str, /, *, withdata: bool = False) -> tuple[memoryview | None, bool, str | None] | None: ...
+    def get_frozen_object(name: str, data: ReadableBuffer | None = None, /) -> types.CodeType: ...
+
+else:
+    def get_frozen_object(name: str, /) -> types.CodeType: ...

crates/red_knot/vendor/typeshed/stdlib/_json.pyi

@@ -0,0 +1,49 @@
+from collections.abc import Callable
+from typing import Any, final
+
+@final
+class make_encoder:
+    @property
+    def sort_keys(self) -> bool: ...
+    @property
+    def skipkeys(self) -> bool: ...
+    @property
+    def key_separator(self) -> str: ...
+    @property
+    def indent(self) -> int | None: ...
+    @property
+    def markers(self) -> dict[int, Any] | None: ...
+    @property
+    def default(self) -> Callable[[Any], Any]: ...
+    @property
+    def encoder(self) -> Callable[[str], str]: ...
+    @property
+    def item_separator(self) -> str: ...
+    def __init__(
+        self,
+        markers: dict[int, Any] | None,
+        default: Callable[[Any], Any],
+        encoder: Callable[[str], str],
+        indent: int | None,
+        key_separator: str,
+        item_separator: str,
+        sort_keys: bool,
+        skipkeys: bool,
+        allow_nan: bool,
+    ) -> None: ...
+    def __call__(self, obj: object, _current_indent_level: int) -> Any: ...
+
+@final
+class make_scanner:
+    object_hook: Any
+    object_pairs_hook: Any
+    parse_int: Any
+    parse_constant: Any
+    parse_float: Any
+    strict: bool
+    # TODO: 'context' needs the attrs above (ducktype), but not __call__.
+    def __init__(self, context: make_scanner) -> None: ...
+    def __call__(self, string: str, index: int) -> tuple[Any, int]: ...
+
+def encode_basestring_ascii(s: str) -> str: ...
+def scanstring(string: str, end: int, strict: bool = ...) -> tuple[str, int]: ...

crates/red_knot/vendor/typeshed/stdlib/_locale.pyi

@@ -0,0 +1,100 @@
+import sys
+from _typeshed import StrPath
+from collections.abc import Mapping
+
+LC_CTYPE: int
+LC_COLLATE: int
+LC_TIME: int
+LC_MONETARY: int
+LC_NUMERIC: int
+LC_ALL: int
+CHAR_MAX: int
+
+def setlocale(category: int, locale: str | None = None, /) -> str: ...
+def localeconv() -> Mapping[str, int | str | list[int]]: ...
+
+if sys.version_info >= (3, 11):
+    def getencoding() -> str: ...
+
+def strcoll(os1: str, os2: str, /) -> int: ...
+def strxfrm(string: str, /) -> str: ...
+
+# native gettext functions
+# https://docs.python.org/3/library/locale.html#access-to-message-catalogs
+# https://github.com/python/cpython/blob/f4c03484da59049eb62a9bf7777b963e2267d187/Modules/_localemodule.c#L626
+if sys.platform != "win32":
+    LC_MESSAGES: int
+
+    ABDAY_1: int
+    ABDAY_2: int
+    ABDAY_3: int
+    ABDAY_4: int
+    ABDAY_5: int
+    ABDAY_6: int
+    ABDAY_7: int
+
+    ABMON_1: int
+    ABMON_2: int
+    ABMON_3: int
+    ABMON_4: int
+    ABMON_5: int
+    ABMON_6: int
+    ABMON_7: int
+    ABMON_8: int
+    ABMON_9: int
+    ABMON_10: int
+    ABMON_11: int
+    ABMON_12: int
+
+    DAY_1: int
+    DAY_2: int
+    DAY_3: int
+    DAY_4: int
+    DAY_5: int
+    DAY_6: int
+    DAY_7: int
+
+    ERA: int
+    ERA_D_T_FMT: int
+    ERA_D_FMT: int
+    ERA_T_FMT: int
+
+    MON_1: int
+    MON_2: int
+    MON_3: int
+    MON_4: int
+    MON_5: int
+    MON_6: int
+    MON_7: int
+    MON_8: int
+    MON_9: int
+    MON_10: int
+    MON_11: int
+    MON_12: int
+
+    CODESET: int
+    D_T_FMT: int
+    D_FMT: int
+    T_FMT: int
+    T_FMT_AMPM: int
+    AM_STR: int
+    PM_STR: int
+
+    RADIXCHAR: int
+    THOUSEP: int
+    YESEXPR: int
+    NOEXPR: int
+    CRNCYSTR: int
+    ALT_DIGITS: int
+
+    def nl_langinfo(key: int, /) -> str: ...
+
+    # This is dependent on `libintl.h` which is a part of `gettext`
+    # system dependency. These functions might be missing.
+    # But, we always say that they are present.
+    def gettext(msg: str, /) -> str: ...
+    def dgettext(domain: str | None, msg: str, /) -> str: ...
+    def dcgettext(domain: str | None, msg: str, category: int, /) -> str: ...
+    def textdomain(domain: str | None, /) -> str: ...
+    def bindtextdomain(domain: str, dir: StrPath | None, /) -> str: ...
+    def bind_textdomain_codeset(domain: str, codeset: str | None, /) -> str | None: ...

crates/red_knot/vendor/typeshed/stdlib/_lsprof.pyi

@@ -0,0 +1,35 @@
+import sys
+from _typeshed import structseq
+from collections.abc import Callable
+from types import CodeType
+from typing import Any, Final, final
+
+class Profiler:
+    def __init__(
+        self, timer: Callable[[], float] | None = None, timeunit: float = 0.0, subcalls: bool = True, builtins: bool = True
+    ) -> None: ...
+    def getstats(self) -> list[profiler_entry]: ...
+    def enable(self, subcalls: bool = True, builtins: bool = True) -> None: ...
+    def disable(self) -> None: ...
+    def clear(self) -> None: ...
+
+@final
+class profiler_entry(structseq[Any], tuple[CodeType | str, int, int, float, float, list[profiler_subentry]]):
+    if sys.version_info >= (3, 10):
+        __match_args__: Final = ("code", "callcount", "reccallcount", "totaltime", "inlinetime", "calls")
+    code: CodeType | str
+    callcount: int
+    reccallcount: int
+    totaltime: float
+    inlinetime: float
+    calls: list[profiler_subentry]
+
+@final
+class profiler_subentry(structseq[Any], tuple[CodeType | str, int, int, float, float]):
+    if sys.version_info >= (3, 10):
+        __match_args__: Final = ("code", "callcount", "reccallcount", "totaltime", "inlinetime")
+    code: CodeType | str
+    callcount: int
+    reccallcount: int
+    totaltime: float
+    inlinetime: float

crates/red_knot/vendor/typeshed/stdlib/_markupbase.pyi

@@ -0,0 +1,16 @@
+import sys
+from typing import Any
+
+class ParserBase:
+    def reset(self) -> None: ...
+    def getpos(self) -> tuple[int, int]: ...
+    def unknown_decl(self, data: str) -> None: ...
+    def parse_comment(self, i: int, report: int = 1) -> int: ...  # undocumented
+    def parse_declaration(self, i: int) -> int: ...  # undocumented
+    def parse_marked_section(self, i: int, report: int = 1) -> int: ...  # undocumented
+    def updatepos(self, i: int, j: int) -> int: ...  # undocumented
+    if sys.version_info < (3, 10):
+        # Removed from ParserBase: https://bugs.python.org/issue31844
+        def error(self, message: str) -> Any: ...  # undocumented
+    lineno: int  # undocumented
+    offset: int  # undocumented

crates/red_knot/vendor/typeshed/stdlib/_msi.pyi

@@ -0,0 +1,92 @@
+import sys
+
+if sys.platform == "win32":
+    class MSIError(Exception): ...
+    # Actual typename View, not exposed by the implementation
+    class _View:
+        def Execute(self, params: _Record | None = ...) -> None: ...
+        def GetColumnInfo(self, kind: int) -> _Record: ...
+        def Fetch(self) -> _Record: ...
+        def Modify(self, mode: int, record: _Record) -> None: ...
+        def Close(self) -> None: ...
+        # Don't exist at runtime
+        __new__: None  # type: ignore[assignment]
+        __init__: None  # type: ignore[assignment]
+
+    # Actual typename SummaryInformation, not exposed by the implementation
+    class _SummaryInformation:
+        def GetProperty(self, field: int) -> int | bytes | None: ...
+        def GetPropertyCount(self) -> int: ...
+        def SetProperty(self, field: int, value: int | str) -> None: ...
+        def Persist(self) -> None: ...
+        # Don't exist at runtime
+        __new__: None  # type: ignore[assignment]
+        __init__: None  # type: ignore[assignment]
+
+    # Actual typename Database, not exposed by the implementation
+    class _Database:
+        def OpenView(self, sql: str) -> _View: ...
+        def Commit(self) -> None: ...
+        def GetSummaryInformation(self, updateCount: int) -> _SummaryInformation: ...
+        def Close(self) -> None: ...
+        # Don't exist at runtime
+        __new__: None  # type: ignore[assignment]
+        __init__: None  # type: ignore[assignment]
+
+    # Actual typename Record, not exposed by the implementation
+    class _Record:
+        def GetFieldCount(self) -> int: ...
+        def GetInteger(self, field: int) -> int: ...
+        def GetString(self, field: int) -> str: ...
+        def SetString(self, field: int, str: str) -> None: ...
+        def SetStream(self, field: int, stream: str) -> None: ...
+        def SetInteger(self, field: int, int: int) -> None: ...
+        def ClearData(self) -> None: ...
+        # Don't exist at runtime
+        __new__: None  # type: ignore[assignment]
+        __init__: None  # type: ignore[assignment]
+
+    def UuidCreate() -> str: ...
+    def FCICreate(cabname: str, files: list[str], /) -> None: ...
+    def OpenDatabase(path: str, persist: int, /) -> _Database: ...
+    def CreateRecord(count: int, /) -> _Record: ...
+
+    MSICOLINFO_NAMES: int
+    MSICOLINFO_TYPES: int
+    MSIDBOPEN_CREATE: int
+    MSIDBOPEN_CREATEDIRECT: int
+    MSIDBOPEN_DIRECT: int
+    MSIDBOPEN_PATCHFILE: int
+    MSIDBOPEN_READONLY: int
+    MSIDBOPEN_TRANSACT: int
+    MSIMODIFY_ASSIGN: int
+    MSIMODIFY_DELETE: int
+    MSIMODIFY_INSERT: int
+    MSIMODIFY_INSERT_TEMPORARY: int
+    MSIMODIFY_MERGE: int
+    MSIMODIFY_REFRESH: int
+    MSIMODIFY_REPLACE: int
+    MSIMODIFY_SEEK: int
+    MSIMODIFY_UPDATE: int
+    MSIMODIFY_VALIDATE: int
+    MSIMODIFY_VALIDATE_DELETE: int
+    MSIMODIFY_VALIDATE_FIELD: int
+    MSIMODIFY_VALIDATE_NEW: int
+
+    PID_APPNAME: int
+    PID_AUTHOR: int
+    PID_CHARCOUNT: int
+    PID_CODEPAGE: int
+    PID_COMMENTS: int
+    PID_CREATE_DTM: int
+    PID_KEYWORDS: int
+    PID_LASTAUTHOR: int
+    PID_LASTPRINTED: int
+    PID_LASTSAVE_DTM: int
+    PID_PAGECOUNT: int
+    PID_REVNUMBER: int
+    PID_SECURITY: int
+    PID_SUBJECT: int
+    PID_TEMPLATE: int
+    PID_TITLE: int
+    PID_WORDCOUNT: int

crates/red_knot/vendor/typeshed/stdlib/_operator.pyi

@@ -0,0 +1,147 @@
+import sys
+from _typeshed import SupportsGetItem
+from collections.abc import Callable, Container, Iterable, MutableMapping, MutableSequence, Sequence
+from typing import Any, AnyStr, Generic, Protocol, SupportsAbs, SupportsIndex, TypeVar, final, overload
+from typing_extensions import ParamSpec, TypeAlias, TypeVarTuple, Unpack
+
+_R = TypeVar("_R")
+_T = TypeVar("_T")
+_T_co = TypeVar("_T_co", covariant=True)
+_T1 = TypeVar("_T1")
+_T2 = TypeVar("_T2")
+_K = TypeVar("_K")
+_V = TypeVar("_V")
+_P = ParamSpec("_P")
+_Ts = TypeVarTuple("_Ts")
+
+# The following protocols return "Any" instead of bool, since the comparison
+# operators can be overloaded to return an arbitrary object. For example,
+# the numpy.array comparison dunders return another numpy.array.
+
+class _SupportsDunderLT(Protocol):
+    def __lt__(self, other: Any, /) -> Any: ...
+
+class _SupportsDunderGT(Protocol):
+    def __gt__(self, other: Any, /) -> Any: ...
+
+class _SupportsDunderLE(Protocol):
+    def __le__(self, other: Any, /) -> Any: ...
+
+class _SupportsDunderGE(Protocol):
+    def __ge__(self, other: Any, /) -> Any: ...
+
+_SupportsComparison: TypeAlias = _SupportsDunderLE | _SupportsDunderGE | _SupportsDunderGT | _SupportsDunderLT
+
+class _SupportsInversion(Protocol[_T_co]):
+    def __invert__(self) -> _T_co: ...
+
+class _SupportsNeg(Protocol[_T_co]):
+    def __neg__(self) -> _T_co: ...
+
+class _SupportsPos(Protocol[_T_co]):
+    def __pos__(self) -> _T_co: ...
+
+# All four comparison functions must have the same signature, or we get false-positive errors
+def lt(a: _SupportsComparison, b: _SupportsComparison, /) -> Any: ...
+def le(a: _SupportsComparison, b: _SupportsComparison, /) -> Any: ...
+def eq(a: object, b: object, /) -> Any: ...
+def ne(a: object, b: object, /) -> Any: ...
+def ge(a: _SupportsComparison, b: _SupportsComparison, /) -> Any: ...
+def gt(a: _SupportsComparison, b: _SupportsComparison, /) -> Any: ...
+def not_(a: object, /) -> bool: ...
+def truth(a: object, /) -> bool: ...
+def is_(a: object, b: object, /) -> bool: ...
+def is_not(a: object, b: object, /) -> bool: ...
+def abs(a: SupportsAbs[_T], /) -> _T: ...
+def add(a: Any, b: Any, /) -> Any: ...
+def and_(a: Any, b: Any, /) -> Any: ...
+def floordiv(a: Any, b: Any, /) -> Any: ...
+def index(a: SupportsIndex, /) -> int: ...
+def inv(a: _SupportsInversion[_T_co], /) -> _T_co: ...
+def invert(a: _SupportsInversion[_T_co], /) -> _T_co: ...
+def lshift(a: Any, b: Any, /) -> Any: ...
+def mod(a: Any, b: Any, /) -> Any: ...
+def mul(a: Any, b: Any, /) -> Any: ...
+def matmul(a: Any, b: Any, /) -> Any: ...
+def neg(a: _SupportsNeg[_T_co], /) -> _T_co: ...
+def or_(a: Any, b: Any, /) -> Any: ...
+def pos(a: _SupportsPos[_T_co], /) -> _T_co: ...
+def pow(a: Any, b: Any, /) -> Any: ...
+def rshift(a: Any, b: Any, /) -> Any: ...
+def sub(a: Any, b: Any, /) -> Any: ...
+def truediv(a: Any, b: Any, /) -> Any: ...
+def xor(a: Any, b: Any, /) -> Any: ...
+def concat(a: Sequence[_T], b: Sequence[_T], /) -> Sequence[_T]: ...
+def contains(a: Container[object], b: object, /) -> bool: ...
+def countOf(a: Iterable[object], b: object, /) -> int: ...
+@overload
+def delitem(a: MutableSequence[Any], b: SupportsIndex, /) -> None: ...
+@overload
+def delitem(a: MutableSequence[Any], b: slice, /) -> None: ...
+@overload
+def delitem(a: MutableMapping[_K, Any], b: _K, /) -> None: ...
+@overload
+def getitem(a: Sequence[_T], b: slice, /) -> Sequence[_T]: ...
+@overload
+def getitem(a: SupportsGetItem[_K, _V], b: _K, /) -> _V: ...
+def indexOf(a: Iterable[_T], b: _T, /) -> int: ...
+@overload
+def setitem(a: MutableSequence[_T], b: SupportsIndex, c: _T, /) -> None: ...
+@overload
+def setitem(a: MutableSequence[_T], b: slice, c: Sequence[_T], /) -> None: ...
+@overload
+def setitem(a: MutableMapping[_K, _V], b: _K, c: _V, /) -> None: ...
+def length_hint(obj: object, default: int = 0, /) -> int: ...
+@final
+class attrgetter(Generic[_T_co]):
+    @overload
+    def __new__(cls, attr: str, /) -> attrgetter[Any]: ...
+    @overload
+    def __new__(cls, attr: str, attr2: str, /) -> attrgetter[tuple[Any, Any]]: ...
+    @overload
+    def __new__(cls, attr: str, attr2: str, attr3: str, /) -> attrgetter[tuple[Any, Any, Any]]: ...
+    @overload
+    def __new__(cls, attr: str, attr2: str, attr3: str, attr4: str, /) -> attrgetter[tuple[Any, Any, Any, Any]]: ...
+    @overload
+    def __new__(cls, attr: str, /, *attrs: str) -> attrgetter[tuple[Any, ...]]: ...
+    def __call__(self, obj: Any, /) -> _T_co: ...
+
+@final
+class itemgetter(Generic[_T_co]):
+    @overload
+    def __new__(cls, item: _T, /) -> itemgetter[_T]: ...
+    @overload
+    def __new__(cls, item1: _T1, item2: _T2, /, *items: Unpack[_Ts]) -> itemgetter[tuple[_T1, _T2, Unpack[_Ts]]]: ...
+    # __key: _KT_contra in SupportsGetItem seems to be causing variance issues, ie:
+    # TypeVar "_KT_contra@SupportsGetItem" is contravariant
+    #   "tuple[int, int]" is incompatible with protocol "SupportsIndex"
+    # preventing [_T_co, ...] instead of [Any, ...]
+    #
+    # A suspected mypy issue prevents using [..., _T] instead of [..., Any] here.
+    # https://github.com/python/mypy/issues/14032
+    def __call__(self, obj: SupportsGetItem[Any, Any]) -> Any: ...
+
+@final
+class methodcaller:
+    def __init__(self, name: str, /, *args: Any, **kwargs: Any) -> None: ...
+    def __call__(self, obj: Any) -> Any: ...
+
+def iadd(a: Any, b: Any, /) -> Any: ...
+def iand(a: Any, b: Any, /) -> Any: ...
+def iconcat(a: Any, b: Any, /) -> Any: ...
+def ifloordiv(a: Any, b: Any, /) -> Any: ...
+def ilshift(a: Any, b: Any, /) -> Any: ...
+def imod(a: Any, b: Any, /) -> Any: ...
+def imul(a: Any, b: Any, /) -> Any: ...
+def imatmul(a: Any, b: Any, /) -> Any: ...
+def ior(a: Any, b: Any, /) -> Any: ...
+def ipow(a: Any, b: Any, /) -> Any: ...
+def irshift(a: Any, b: Any, /) -> Any: ...
+def isub(a: Any, b: Any, /) -> Any: ...
+def itruediv(a: Any, b: Any, /) -> Any: ...
+def ixor(a: Any, b: Any, /) -> Any: ...
+
+if sys.version_info >= (3, 11):
+    def call(obj: Callable[_P, _R], /, *args: _P.args, **kwargs: _P.kwargs) -> _R: ...
+
+def _compare_digest(a: AnyStr, b: AnyStr, /) -> bool: ...

crates/red_knot/vendor/typeshed/stdlib/_osx_support.pyi

@@ -0,0 +1,34 @@
+from collections.abc import Iterable, Sequence
+from typing import TypeVar
+
+_T = TypeVar("_T")
+_K = TypeVar("_K")
+_V = TypeVar("_V")
+
+__all__ = ["compiler_fixup", "customize_config_vars", "customize_compiler", "get_platform_osx"]
+
+_UNIVERSAL_CONFIG_VARS: tuple[str, ...]  # undocumented
+_COMPILER_CONFIG_VARS: tuple[str, ...]  # undocumented
+_INITPRE: str  # undocumented
+
+def _find_executable(executable: str, path: str | None = None) -> str | None: ...  # undocumented
+def _read_output(commandstring: str, capture_stderr: bool = False) -> str | None: ...  # undocumented
+def _find_build_tool(toolname: str) -> str: ...  # undocumented
+
+_SYSTEM_VERSION: str | None  # undocumented
+
+def _get_system_version() -> str: ...  # undocumented
+def _remove_original_values(_config_vars: dict[str, str]) -> None: ...  # undocumented
+def _save_modified_value(_config_vars: dict[str, str], cv: str, newvalue: str) -> None: ...  # undocumented
+def _supports_universal_builds() -> bool: ...  # undocumented
+def _find_appropriate_compiler(_config_vars: dict[str, str]) -> dict[str, str]: ...  # undocumented
+def _remove_universal_flags(_config_vars: dict[str, str]) -> dict[str, str]: ...  # undocumented
+def _remove_unsupported_archs(_config_vars: dict[str, str]) -> dict[str, str]: ...  # undocumented
+def _override_all_archs(_config_vars: dict[str, str]) -> dict[str, str]: ...  # undocumented
+def _check_for_unavailable_sdk(_config_vars: dict[str, str]) -> dict[str, str]: ...  # undocumented
+def compiler_fixup(compiler_so: Iterable[str], cc_args: Sequence[str]) -> list[str]: ...
+def customize_config_vars(_config_vars: dict[str, str]) -> dict[str, str]: ...
+def customize_compiler(_config_vars: dict[str, str]) -> dict[str, str]: ...
+def get_platform_osx(
+    _config_vars: dict[str, str], osname: _T, release: _K, machine: _V
+) -> tuple[str | _T, str | _K, str | _V]: ...

crates/red_knot/vendor/typeshed/stdlib/_posixsubprocess.pyi

@@ -0,0 +1,33 @@
+import sys
+from _typeshed import StrOrBytesPath
+from collections.abc import Callable, Sequence
+from typing import SupportsIndex
+
+if sys.platform != "win32":
+    def cloexec_pipe() -> tuple[int, int]: ...
+    def fork_exec(
+        args: Sequence[StrOrBytesPath] | None,
+        executable_list: Sequence[bytes],
+        close_fds: bool,
+        pass_fds: tuple[int, ...],
+        cwd: str,
+        env: Sequence[bytes] | None,
+        p2cread: int,
+        p2cwrite: int,
+        c2pread: int,
+        c2pwrite: int,
+        errread: int,
+        errwrite: int,
+        errpipe_read: int,
+        errpipe_write: int,
+        restore_signals: int,
+        call_setsid: int,
+        pgid_to_set: int,
+        gid: SupportsIndex | None,
+        extra_groups: list[int] | None,
+        uid: SupportsIndex | None,
+        child_umask: int,
+        preexec_fn: Callable[[], None],
+        allow_vfork: bool,
+        /,
+    ) -> int: ...

crates/red_knot/vendor/typeshed/stdlib/_py_abc.pyi

@@ -0,0 +1,14 @@
+import _typeshed
+from typing import Any, NewType, TypeVar
+
+_T = TypeVar("_T")
+
+_CacheToken = NewType("_CacheToken", int)
+
+def get_cache_token() -> _CacheToken: ...
+
+class ABCMeta(type):
+    def __new__(
+        mcls: type[_typeshed.Self], name: str, bases: tuple[type[Any], ...], namespace: dict[str, Any], /
+    ) -> _typeshed.Self: ...
+    def register(cls, subclass: type[_T]) -> type[_T]: ...

crates/red_knot/vendor/typeshed/stdlib/_pydecimal.pyi

@@ -0,0 +1,43 @@
+# This is a slight lie, the implementations aren't exactly identical
+# However, in all likelihood, the differences are inconsequential
+from _decimal import *
+
+__all__ = [
+    "Decimal",
+    "Context",
+    "DecimalTuple",
+    "DefaultContext",
+    "BasicContext",
+    "ExtendedContext",
+    "DecimalException",
+    "Clamped",
+    "InvalidOperation",
+    "DivisionByZero",
+    "Inexact",
+    "Rounded",
+    "Subnormal",
+    "Overflow",
+    "Underflow",
+    "FloatOperation",
+    "DivisionImpossible",
+    "InvalidContext",
+    "ConversionSyntax",
+    "DivisionUndefined",
+    "ROUND_DOWN",
+    "ROUND_HALF_UP",
+    "ROUND_HALF_EVEN",
+    "ROUND_CEILING",
+    "ROUND_FLOOR",
+    "ROUND_UP",
+    "ROUND_HALF_DOWN",
+    "ROUND_05UP",
+    "setcontext",
+    "getcontext",
+    "localcontext",
+    "MAX_PREC",
+    "MAX_EMAX",
+    "MIN_EMIN",
+    "MIN_ETINY",
+    "HAVE_THREADS",
+    "HAVE_CONTEXTVAR",
+]

crates/red_knot/vendor/typeshed/stdlib/_random.pyi

@@ -0,0 +1,12 @@
+from typing_extensions import TypeAlias
+
+# Actually Tuple[(int,) * 625]
+_State: TypeAlias = tuple[int, ...]
+
+class Random:
+    def __init__(self, seed: object = ...) -> None: ...
+    def seed(self, n: object = None, /) -> None: ...
+    def getstate(self) -> _State: ...
+    def setstate(self, state: _State, /) -> None: ...
+    def random(self) -> float: ...
+    def getrandbits(self, k: int, /) -> int: ...

crates/red_knot/vendor/typeshed/stdlib/_sitebuiltins.pyi

@@ -0,0 +1,16 @@
+from collections.abc import Iterable
+from typing import ClassVar, Literal, NoReturn
+
+class Quitter:
+    name: str
+    eof: str
+    def __init__(self, name: str, eof: str) -> None: ...
+    def __call__(self, code: int | None = None) -> NoReturn: ...
+
+class _Printer:
+    MAXLINES: ClassVar[Literal[23]]
+    def __init__(self, name: str, data: str, files: Iterable[str] = (), dirs: Iterable[str] = ()) -> None: ...
+    def __call__(self) -> None: ...
+
+class _Helper:
+    def __call__(self, request: object) -> None: ...

crates/red_knot/vendor/typeshed/stdlib/_socket.pyi

@@ -0,0 +1,803 @@
+import sys
+from _typeshed import ReadableBuffer, WriteableBuffer
+from collections.abc import Iterable
+from typing import Any, SupportsIndex, overload
+from typing_extensions import TypeAlias
+
+_CMSG: TypeAlias = tuple[int, int, bytes]
+_CMSGArg: TypeAlias = tuple[int, int, ReadableBuffer]
+
+# Addresses can be either tuples of varying lengths (AF_INET, AF_INET6,
+# AF_NETLINK, AF_TIPC) or strings/buffers (AF_UNIX).
+# See getsockaddrarg() in socketmodule.c.
+_Address: TypeAlias = tuple[Any, ...] | str | ReadableBuffer
+_RetAddress: TypeAlias = Any
+
+# ===== Constants =====
+# This matches the order in the CPython documentation
+# https://docs.python.org/3/library/socket.html#constants
+
+if sys.platform != "win32":
+    AF_UNIX: int
+
+AF_INET: int
+AF_INET6: int
+
+AF_UNSPEC: int
+
+SOCK_STREAM: int
+SOCK_DGRAM: int
+SOCK_RAW: int
+SOCK_RDM: int
+SOCK_SEQPACKET: int
+
+if sys.platform == "linux":
+    # Availability: Linux >= 2.6.27
+    SOCK_CLOEXEC: int
+    SOCK_NONBLOCK: int
+
+# --------------------
+# Many constants of these forms, documented in the Unix documentation on
+# sockets and/or the IP protocol, are also defined in the socket module.
+# SO_*
+# socket.SOMAXCONN
+# MSG_*
+# SOL_*
+# SCM_*
+# IPPROTO_*
+# IPPORT_*
+# INADDR_*
+# IP_*
+# IPV6_*
+# EAI_*
+# AI_*
+# NI_*
+# TCP_*
+# --------------------
+
+SO_ACCEPTCONN: int
+SO_BROADCAST: int
+SO_DEBUG: int
+SO_DONTROUTE: int
+SO_ERROR: int
+SO_KEEPALIVE: int
+SO_LINGER: int
+SO_OOBINLINE: int
+SO_RCVBUF: int
+SO_RCVLOWAT: int
+SO_RCVTIMEO: int
+SO_REUSEADDR: int
+SO_SNDBUF: int
+SO_SNDLOWAT: int
+SO_SNDTIMEO: int
+SO_TYPE: int
+SO_USELOOPBACK: int
+if sys.platform == "win32":
+    SO_EXCLUSIVEADDRUSE: int
+if sys.platform != "win32":
+    SO_REUSEPORT: int
+if sys.platform != "win32" and sys.platform != "darwin":
+    SO_BINDTODEVICE: int
+    SO_DOMAIN: int
+    SO_MARK: int
+    SO_PASSCRED: int
+    SO_PASSSEC: int
+    SO_PEERCRED: int
+    SO_PEERSEC: int
+    SO_PRIORITY: int
+    SO_PROTOCOL: int
+    SO_SETFIB: int
+
+SOMAXCONN: int
+
+MSG_CTRUNC: int
+MSG_DONTROUTE: int
+MSG_OOB: int
+MSG_PEEK: int
+MSG_TRUNC: int
+MSG_WAITALL: int
+if sys.platform != "win32":
+    MSG_DONTWAIT: int
+    MSG_EOF: int
+    MSG_EOR: int
+    MSG_NOSIGNAL: int  # Sometimes this exists on darwin, sometimes not
+if sys.platform != "darwin":
+    MSG_BCAST: int
+    MSG_ERRQUEUE: int
+    MSG_MCAST: int
+if sys.platform != "win32" and sys.platform != "darwin":
+    MSG_BTAG: int
+    MSG_CMSG_CLOEXEC: int
+    MSG_CONFIRM: int
+    MSG_ETAG: int
+    MSG_FASTOPEN: int
+    MSG_MORE: int
+    MSG_NOTIFICATION: int
+
+SOL_IP: int
+SOL_SOCKET: int
+SOL_TCP: int
+SOL_UDP: int
+if sys.platform != "win32" and sys.platform != "darwin":
+    SOL_ATALK: int
+    SOL_AX25: int
+    SOL_HCI: int
+    SOL_IPX: int
+    SOL_NETROM: int
+    SOL_ROSE: int
+
+if sys.platform != "win32":
+    SCM_CREDS: int
+    SCM_RIGHTS: int
+if sys.platform != "win32" and sys.platform != "darwin":
+    SCM_CREDENTIALS: int
+
+IPPROTO_ICMP: int
+IPPROTO_IP: int
+IPPROTO_RAW: int
+IPPROTO_TCP: int
+IPPROTO_UDP: int
+IPPROTO_AH: int
+IPPROTO_DSTOPTS: int
+IPPROTO_EGP: int
+IPPROTO_ESP: int
+IPPROTO_FRAGMENT: int
+IPPROTO_GGP: int
+IPPROTO_HOPOPTS: int
+IPPROTO_ICMPV6: int
+IPPROTO_IDP: int
+IPPROTO_IGMP: int
+IPPROTO_IPV4: int
+IPPROTO_IPV6: int
+IPPROTO_MAX: int
+IPPROTO_ND: int
+IPPROTO_NONE: int
+IPPROTO_PIM: int
+IPPROTO_PUP: int
+IPPROTO_ROUTING: int
+IPPROTO_SCTP: int
+if sys.platform != "darwin":
+    IPPROTO_CBT: int
+    IPPROTO_ICLFXBM: int
+    IPPROTO_IGP: int
+    IPPROTO_L2TP: int
+    IPPROTO_PGM: int
+    IPPROTO_RDP: int
+    IPPROTO_ST: int
+if sys.platform != "win32":
+    IPPROTO_EON: int
+    IPPROTO_GRE: int
+    IPPROTO_HELLO: int
+    IPPROTO_IPCOMP: int
+    IPPROTO_IPIP: int
+    IPPROTO_RSVP: int
+    IPPROTO_TP: int
+    IPPROTO_XTP: int
+if sys.platform != "win32" and sys.platform != "darwin":
+    IPPROTO_BIP: int
+    IPPROTO_MOBILE: int
+    IPPROTO_VRRP: int
+if sys.version_info >= (3, 9) and sys.platform == "linux":
+    # Availability: Linux >= 2.6.20, FreeBSD >= 10.1
+    IPPROTO_UDPLITE: int
+if sys.version_info >= (3, 10) and sys.platform == "linux":
+    IPPROTO_MPTCP: int
+
+IPPORT_RESERVED: int
+IPPORT_USERRESERVED: int
+
+INADDR_ALLHOSTS_GROUP: int
+INADDR_ANY: int
+INADDR_BROADCAST: int
+INADDR_LOOPBACK: int
+INADDR_MAX_LOCAL_GROUP: int
+INADDR_NONE: int
+INADDR_UNSPEC_GROUP: int
+
+IP_ADD_MEMBERSHIP: int
+IP_DROP_MEMBERSHIP: int
+IP_HDRINCL: int
+IP_MULTICAST_IF: int
+IP_MULTICAST_LOOP: int
+IP_MULTICAST_TTL: int
+IP_OPTIONS: int
+IP_RECVDSTADDR: int
+if sys.version_info >= (3, 10):
+    IP_RECVTOS: int
+elif sys.platform != "win32" and sys.platform != "darwin":
+    IP_RECVTOS: int
+IP_TOS: int
+IP_TTL: int
+if sys.platform != "win32":
+    IP_DEFAULT_MULTICAST_LOOP: int
+    IP_DEFAULT_MULTICAST_TTL: int
+    IP_MAX_MEMBERSHIPS: int
+    IP_RECVOPTS: int
+    IP_RECVRETOPTS: int
+    IP_RETOPTS: int
+if sys.platform != "win32" and sys.platform != "darwin":
+    IP_TRANSPARENT: int
+    IP_BIND_ADDRESS_NO_PORT: int
+if sys.version_info >= (3, 12):
+    IP_ADD_SOURCE_MEMBERSHIP: int
+    IP_BLOCK_SOURCE: int
+    IP_DROP_SOURCE_MEMBERSHIP: int
+    IP_PKTINFO: int
+    IP_UNBLOCK_SOURCE: int
+
+IPV6_CHECKSUM: int
+IPV6_JOIN_GROUP: int
+IPV6_LEAVE_GROUP: int
+IPV6_MULTICAST_HOPS: int
+IPV6_MULTICAST_IF: int
+IPV6_MULTICAST_LOOP: int
+IPV6_RECVTCLASS: int
+IPV6_TCLASS: int
+IPV6_UNICAST_HOPS: int
+IPV6_V6ONLY: int
+if sys.version_info >= (3, 9) or sys.platform != "darwin":
+    IPV6_DONTFRAG: int
+    IPV6_HOPLIMIT: int
+    IPV6_HOPOPTS: int
+    IPV6_PKTINFO: int
+    IPV6_RECVRTHDR: int
+    IPV6_RTHDR: int
+if sys.platform != "win32":
+    IPV6_RTHDR_TYPE_0: int
+    if sys.version_info >= (3, 9) or sys.platform != "darwin":
+        IPV6_DSTOPTS: int
+        IPV6_NEXTHOP: int
+        IPV6_PATHMTU: int
+        IPV6_RECVDSTOPTS: int
+        IPV6_RECVHOPLIMIT: int
+        IPV6_RECVHOPOPTS: int
+        IPV6_RECVPATHMTU: int
+        IPV6_RECVPKTINFO: int
+        IPV6_RTHDRDSTOPTS: int
+        IPV6_USE_MIN_MTU: int
+
+EAI_AGAIN: int
+EAI_BADFLAGS: int
+EAI_FAIL: int
+EAI_FAMILY: int
+EAI_MEMORY: int
+EAI_NODATA: int
+EAI_NONAME: int
+EAI_SERVICE: int
+EAI_SOCKTYPE: int
+if sys.platform != "win32":
+    EAI_ADDRFAMILY: int
+    EAI_BADHINTS: int
+    EAI_MAX: int
+    EAI_OVERFLOW: int
+    EAI_PROTOCOL: int
+    EAI_SYSTEM: int
+
+AI_ADDRCONFIG: int
+AI_ALL: int
+AI_CANONNAME: int
+AI_NUMERICHOST: int
+AI_NUMERICSERV: int
+AI_PASSIVE: int
+AI_V4MAPPED: int
+if sys.platform != "win32":
+    AI_DEFAULT: int
+    AI_MASK: int
+    AI_V4MAPPED_CFG: int
+
+NI_DGRAM: int
+NI_MAXHOST: int
+NI_MAXSERV: int
+NI_NAMEREQD: int
+NI_NOFQDN: int
+NI_NUMERICHOST: int
+NI_NUMERICSERV: int
+
+TCP_FASTOPEN: int
+TCP_KEEPCNT: int
+TCP_KEEPINTVL: int
+TCP_MAXSEG: int
+TCP_NODELAY: int
+if sys.platform != "win32":
+    TCP_NOTSENT_LOWAT: int
+if sys.platform != "darwin":
+    TCP_KEEPIDLE: int
+if sys.version_info >= (3, 10) and sys.platform == "darwin":
+    TCP_KEEPALIVE: int
+if sys.version_info >= (3, 11) and sys.platform == "darwin":
+    TCP_CONNECTION_INFO: int
+
+if sys.platform != "win32" and sys.platform != "darwin":
+    TCP_CONGESTION: int
+    TCP_CORK: int
+    TCP_DEFER_ACCEPT: int
+    TCP_INFO: int
+    TCP_LINGER2: int
+    TCP_QUICKACK: int
+    TCP_SYNCNT: int
+    TCP_USER_TIMEOUT: int
+    TCP_WINDOW_CLAMP: int
+
+# --------------------
+# Specifically documented constants
+# --------------------
+
+if sys.platform == "linux":
+    # Availability: Linux >= 2.6.25, NetBSD >= 8
+    AF_CAN: int
+    PF_CAN: int
+    SOL_CAN_BASE: int
+    SOL_CAN_RAW: int
+    CAN_EFF_FLAG: int
+    CAN_EFF_MASK: int
+    CAN_ERR_FLAG: int
+    CAN_ERR_MASK: int
+    CAN_RAW: int
+    CAN_RAW_ERR_FILTER: int
+    CAN_RAW_FILTER: int
+    CAN_RAW_LOOPBACK: int
+    CAN_RAW_RECV_OWN_MSGS: int
+    CAN_RTR_FLAG: int
+    CAN_SFF_MASK: int
+
+if sys.platform == "linux":
+    # Availability: Linux >= 2.6.25
+    CAN_BCM: int
+    CAN_BCM_TX_SETUP: int
+    CAN_BCM_TX_DELETE: int
+    CAN_BCM_TX_READ: int
+    CAN_BCM_TX_SEND: int
+    CAN_BCM_RX_SETUP: int
+    CAN_BCM_RX_DELETE: int
+    CAN_BCM_RX_READ: int
+    CAN_BCM_TX_STATUS: int
+    CAN_BCM_TX_EXPIRED: int
+    CAN_BCM_RX_STATUS: int
+    CAN_BCM_RX_TIMEOUT: int
+    CAN_BCM_RX_CHANGED: int
+    CAN_BCM_SETTIMER: int
+    CAN_BCM_STARTTIMER: int
+    CAN_BCM_TX_COUNTEVT: int
+    CAN_BCM_TX_ANNOUNCE: int
+    CAN_BCM_TX_CP_CAN_ID: int
+    CAN_BCM_RX_FILTER_ID: int
+    CAN_BCM_RX_CHECK_DLC: int
+    CAN_BCM_RX_NO_AUTOTIMER: int
+    CAN_BCM_RX_ANNOUNCE_RESUME: int
+    CAN_BCM_TX_RESET_MULTI_IDX: int
+    CAN_BCM_RX_RTR_FRAME: int
+    CAN_BCM_CAN_FD_FRAME: int
+
+if sys.platform == "linux":
+    # Availability: Linux >= 3.6
+    CAN_RAW_FD_FRAMES: int
+
+if sys.platform == "linux" and sys.version_info >= (3, 9):
+    # Availability: Linux >= 4.1
+    CAN_RAW_JOIN_FILTERS: int
+
+if sys.platform == "linux":
+    # Availability: Linux >= 2.6.25
+    CAN_ISOTP: int
+
+if sys.platform == "linux" and sys.version_info >= (3, 9):
+    # Availability: Linux >= 5.4
+    CAN_J1939: int
+
+    J1939_MAX_UNICAST_ADDR: int
+    J1939_IDLE_ADDR: int
+    J1939_NO_ADDR: int
+    J1939_NO_NAME: int
+    J1939_PGN_REQUEST: int
+    J1939_PGN_ADDRESS_CLAIMED: int
+    J1939_PGN_ADDRESS_COMMANDED: int
+    J1939_PGN_PDU1_MAX: int
+    J1939_PGN_MAX: int
+    J1939_NO_PGN: int
+
+    SO_J1939_FILTER: int
+    SO_J1939_PROMISC: int
+    SO_J1939_SEND_PRIO: int
+    SO_J1939_ERRQUEUE: int
+
+    SCM_J1939_DEST_ADDR: int
+    SCM_J1939_DEST_NAME: int
+    SCM_J1939_PRIO: int
+    SCM_J1939_ERRQUEUE: int
+
+    J1939_NLA_PAD: int
+    J1939_NLA_BYTES_ACKED: int
+    J1939_EE_INFO_NONE: int
+    J1939_EE_INFO_TX_ABORT: int
+    J1939_FILTER_MAX: int
+
+if sys.version_info >= (3, 12) and sys.platform != "linux" and sys.platform != "win32" and sys.platform != "darwin":
+    # Availability: FreeBSD >= 14.0
+    AF_DIVERT: int
+    PF_DIVERT: int
+
+if sys.platform == "linux":
+    # Availability: Linux >= 2.2
+    AF_PACKET: int
+    PF_PACKET: int
+    PACKET_BROADCAST: int
+    PACKET_FASTROUTE: int
+    PACKET_HOST: int
+    PACKET_LOOPBACK: int
+    PACKET_MULTICAST: int
+    PACKET_OTHERHOST: int
+    PACKET_OUTGOING: int
+
+if sys.version_info >= (3, 12) and sys.platform == "linux":
+    ETH_P_ALL: int
+
+if sys.platform == "linux":
+    # Availability: Linux >= 2.6.30
+    AF_RDS: int
+    PF_RDS: int
+    SOL_RDS: int
+    RDS_CANCEL_SENT_TO: int
+    RDS_CMSG_RDMA_ARGS: int
+    RDS_CMSG_RDMA_DEST: int
+    RDS_CMSG_RDMA_MAP: int
+    RDS_CMSG_RDMA_STATUS: int
+    RDS_CMSG_RDMA_UPDATE: int
+    RDS_CONG_MONITOR: int
+    RDS_FREE_MR: int
+    RDS_GET_MR: int
+    RDS_GET_MR_FOR_DEST: int
+    RDS_RDMA_DONTWAIT: int
+    RDS_RDMA_FENCE: int
+    RDS_RDMA_INVALIDATE: int
+    RDS_RDMA_NOTIFY_ME: int
+    RDS_RDMA_READWRITE: int
+    RDS_RDMA_SILENT: int
+    RDS_RDMA_USE_ONCE: int
+    RDS_RECVERR: int
+
+if sys.platform == "win32":
+    SIO_RCVALL: int
+    SIO_KEEPALIVE_VALS: int
+    SIO_LOOPBACK_FAST_PATH: int
+    RCVALL_MAX: int
+    RCVALL_OFF: int
+    RCVALL_ON: int
+    RCVALL_SOCKETLEVELONLY: int
+
+if sys.platform == "linux":
+    AF_TIPC: int
+    SOL_TIPC: int
+    TIPC_ADDR_ID: int
+    TIPC_ADDR_NAME: int
+    TIPC_ADDR_NAMESEQ: int
+    TIPC_CFG_SRV: int
+    TIPC_CLUSTER_SCOPE: int
+    TIPC_CONN_TIMEOUT: int
+    TIPC_CRITICAL_IMPORTANCE: int
+    TIPC_DEST_DROPPABLE: int
+    TIPC_HIGH_IMPORTANCE: int
+    TIPC_IMPORTANCE: int
+    TIPC_LOW_IMPORTANCE: int
+    TIPC_MEDIUM_IMPORTANCE: int
+    TIPC_NODE_SCOPE: int
+    TIPC_PUBLISHED: int
+    TIPC_SRC_DROPPABLE: int
+    TIPC_SUBSCR_TIMEOUT: int
+    TIPC_SUB_CANCEL: int
+    TIPC_SUB_PORTS: int
+    TIPC_SUB_SERVICE: int
+    TIPC_TOP_SRV: int
+    TIPC_WAIT_FOREVER: int
+    TIPC_WITHDRAWN: int
+    TIPC_ZONE_SCOPE: int
+
+if sys.platform == "linux":
+    # Availability: Linux >= 2.6.38
+    AF_ALG: int
+    SOL_ALG: int
+    ALG_OP_DECRYPT: int
+    ALG_OP_ENCRYPT: int
+    ALG_OP_SIGN: int
+    ALG_OP_VERIFY: int
+    ALG_SET_AEAD_ASSOCLEN: int
+    ALG_SET_AEAD_AUTHSIZE: int
+    ALG_SET_IV: int
+    ALG_SET_KEY: int
+    ALG_SET_OP: int
+    ALG_SET_PUBKEY: int
+
+if sys.platform == "linux":
+    # Availability: Linux >= 4.8 (or maybe 3.9, CPython docs are confusing)
+    AF_VSOCK: int
+    IOCTL_VM_SOCKETS_GET_LOCAL_CID: int
+    VMADDR_CID_ANY: int
+    VMADDR_CID_HOST: int
+    VMADDR_PORT_ANY: int
+    SO_VM_SOCKETS_BUFFER_MAX_SIZE: int
+    SO_VM_SOCKETS_BUFFER_SIZE: int
+    SO_VM_SOCKETS_BUFFER_MIN_SIZE: int
+    VM_SOCKETS_INVALID_VERSION: int  # undocumented
+
+if sys.platform != "win32" or sys.version_info >= (3, 9):
+    # Documented as only available on BSD, macOS, but empirically sometimes
+    # available on Windows
+    AF_LINK: int
+
+has_ipv6: bool
+
+if sys.platform != "darwin":
+    if sys.platform != "win32" or sys.version_info >= (3, 9):
+        BDADDR_ANY: str
+        BDADDR_LOCAL: str
+
+if sys.platform != "win32" and sys.platform != "darwin":
+    HCI_FILTER: int  # not in NetBSD or DragonFlyBSD
+    HCI_TIME_STAMP: int  # not in FreeBSD, NetBSD, or DragonFlyBSD
+    HCI_DATA_DIR: int  # not in FreeBSD, NetBSD, or DragonFlyBSD
+
+if sys.platform == "linux":
+    AF_QIPCRTR: int  # Availability: Linux >= 4.7
+
+if sys.version_info >= (3, 11) and sys.platform != "linux" and sys.platform != "win32" and sys.platform != "darwin":
+    # FreeBSD
+    SCM_CREDS2: int
+    LOCAL_CREDS: int
+    LOCAL_CREDS_PERSISTENT: int
+
+if sys.version_info >= (3, 11) and sys.platform == "linux":
+    SO_INCOMING_CPU: int  # Availability: Linux >= 3.9
+
+if sys.version_info >= (3, 12) and sys.platform == "win32":
+    # Availability: Windows
+    AF_HYPERV: int
+    HV_PROTOCOL_RAW: int
+    HVSOCKET_CONNECT_TIMEOUT: int
+    HVSOCKET_CONNECT_TIMEOUT_MAX: int
+    HVSOCKET_CONNECTED_SUSPEND: int
+    HVSOCKET_ADDRESS_FLAG_PASSTHRU: int
+    HV_GUID_ZERO: str
+    HV_GUID_WILDCARD: str
+    HV_GUID_BROADCAST: str
+    HV_GUID_CHILDREN: str
+    HV_GUID_LOOPBACK: str
+    HV_GUID_PARENT: str
+
+if sys.version_info >= (3, 12):
+    if sys.platform != "win32":
+        # Availability: Linux, FreeBSD, macOS
+        ETHERTYPE_ARP: int
+        ETHERTYPE_IP: int
+        ETHERTYPE_IPV6: int
+        ETHERTYPE_VLAN: int
+
+# --------------------
+# Semi-documented constants
+# These are alluded to under the "Socket families" section in the docs
+# https://docs.python.org/3/library/socket.html#socket-families
+# --------------------
+
+if sys.platform == "linux":
+    # Netlink is defined by Linux
+    AF_NETLINK: int
+    NETLINK_ARPD: int
+    NETLINK_CRYPTO: int
+    NETLINK_DNRTMSG: int
+    NETLINK_FIREWALL: int
+    NETLINK_IP6_FW: int
+    NETLINK_NFLOG: int
+    NETLINK_ROUTE6: int
+    NETLINK_ROUTE: int
+    NETLINK_SKIP: int
+    NETLINK_TAPBASE: int
+    NETLINK_TCPDIAG: int
+    NETLINK_USERSOCK: int
+    NETLINK_W1: int
+    NETLINK_XFRM: int
+
+if sys.platform == "darwin":
+    PF_SYSTEM: int
+    SYSPROTO_CONTROL: int
+
+if sys.platform != "darwin":
+    if sys.version_info >= (3, 9) or sys.platform != "win32":
+        AF_BLUETOOTH: int
+
+if sys.platform != "win32" and sys.platform != "darwin":
+    # Linux and some BSD support is explicit in the docs
+    # Windows and macOS do not support in practice
+    BTPROTO_HCI: int
+    BTPROTO_L2CAP: int
+    BTPROTO_SCO: int  # not in FreeBSD
+if sys.platform != "darwin":
+    if sys.version_info >= (3, 9) or sys.platform != "win32":
+        BTPROTO_RFCOMM: int
+
+if sys.version_info >= (3, 9) and sys.platform == "linux":
+    UDPLITE_RECV_CSCOV: int
+    UDPLITE_SEND_CSCOV: int
+
+# --------------------
+# Documented under socket.shutdown
+# --------------------
+SHUT_RD: int
+SHUT_RDWR: int
+SHUT_WR: int
+
+# --------------------
+# Undocumented constants
+# --------------------
+
+# Undocumented address families
+AF_APPLETALK: int
+AF_DECnet: int
+AF_IPX: int
+AF_SNA: int
+
+if sys.platform != "win32":
+    AF_ROUTE: int
+    AF_SYSTEM: int
+
+if sys.platform != "darwin":
+    AF_IRDA: int
+
+if sys.platform != "win32" and sys.platform != "darwin":
+    AF_AAL5: int
+    AF_ASH: int
+    AF_ATMPVC: int
+    AF_ATMSVC: int
+    AF_AX25: int
+    AF_BRIDGE: int
+    AF_ECONET: int
+    AF_KEY: int
+    AF_LLC: int
+    AF_NETBEUI: int
+    AF_NETROM: int
+    AF_PPPOX: int
+    AF_ROSE: int
+    AF_SECURITY: int
+    AF_WANPIPE: int
+    AF_X25: int
+
+# Miscellaneous undocumented
+
+if sys.platform != "win32":
+    LOCAL_PEERCRED: int
+
+if sys.platform != "win32" and sys.platform != "darwin":
+    IPX_TYPE: int
+
+# ===== Exceptions =====
+
+error = OSError
+
+class herror(error): ...
+class gaierror(error): ...
+
+if sys.version_info >= (3, 10):
+    timeout = TimeoutError
+else:
+    class timeout(error): ...
+
+# ===== Classes =====
+
+class socket:
+    @property
+    def family(self) -> int: ...
+    @property
+    def type(self) -> int: ...
+    @property
+    def proto(self) -> int: ...
+    @property
+    def timeout(self) -> float | None: ...
+    if sys.platform == "win32":
+        def __init__(
+            self, family: int = ..., type: int = ..., proto: int = ..., fileno: SupportsIndex | bytes | None = ...
+        ) -> None: ...
+    else:
+        def __init__(self, family: int = ..., type: int = ..., proto: int = ..., fileno: SupportsIndex | None = ...) -> None: ...
+
+    def bind(self, address: _Address, /) -> None: ...
+    def close(self) -> None: ...
+    def connect(self, address: _Address, /) -> None: ...
+    def connect_ex(self, address: _Address, /) -> int: ...
+    def detach(self) -> int: ...
+    def fileno(self) -> int: ...
+    def getpeername(self) -> _RetAddress: ...
+    def getsockname(self) -> _RetAddress: ...
+    @overload
+    def getsockopt(self, level: int, optname: int, /) -> int: ...
+    @overload
+    def getsockopt(self, level: int, optname: int, buflen: int, /) -> bytes: ...
+    def getblocking(self) -> bool: ...
+    def gettimeout(self) -> float | None: ...
+    if sys.platform == "win32":
+        def ioctl(self, control: int, option: int | tuple[int, int, int] | bool, /) -> None: ...
+
+    def listen(self, backlog: int = ..., /) -> None: ...
+    def recv(self, bufsize: int, flags: int = ..., /) -> bytes: ...
+    def recvfrom(self, bufsize: int, flags: int = ..., /) -> tuple[bytes, _RetAddress]: ...
+    if sys.platform != "win32":
+        def recvmsg(self, bufsize: int, ancbufsize: int = ..., flags: int = ..., /) -> tuple[bytes, list[_CMSG], int, Any]: ...
+        def recvmsg_into(
+            self, buffers: Iterable[WriteableBuffer], ancbufsize: int = ..., flags: int = ..., /
+        ) -> tuple[int, list[_CMSG], int, Any]: ...
+
+    def recvfrom_into(self, buffer: WriteableBuffer, nbytes: int = ..., flags: int = ...) -> tuple[int, _RetAddress]: ...
+    def recv_into(self, buffer: WriteableBuffer, nbytes: int = ..., flags: int = ...) -> int: ...
+    def send(self, data: ReadableBuffer, flags: int = ..., /) -> int: ...
+    def sendall(self, data: ReadableBuffer, flags: int = ..., /) -> None: ...
+    @overload
+    def sendto(self, data: ReadableBuffer, address: _Address, /) -> int: ...
+    @overload
+    def sendto(self, data: ReadableBuffer, flags: int, address: _Address, /) -> int: ...
+    if sys.platform != "win32":
+        def sendmsg(
+            self,
+            buffers: Iterable[ReadableBuffer],
+            ancdata: Iterable[_CMSGArg] = ...,
+            flags: int = ...,
+            address: _Address | None = ...,
+            /,
+        ) -> int: ...
+    if sys.platform == "linux":
+        def sendmsg_afalg(
+            self, msg: Iterable[ReadableBuffer] = ..., *, op: int, iv: Any = ..., assoclen: int = ..., flags: int = ...
+        ) -> int: ...
+
+    def setblocking(self, flag: bool, /) -> None: ...
+    def settimeout(self, value: float | None, /) -> None: ...
+    @overload
+    def setsockopt(self, level: int, optname: int, value: int | ReadableBuffer, /) -> None: ...
+    @overload
+    def setsockopt(self, level: int, optname: int, value: None, optlen: int, /) -> None: ...
+    if sys.platform == "win32":
+        def share(self, process_id: int, /) -> bytes: ...
+
+    def shutdown(self, how: int, /) -> None: ...
+
+SocketType = socket
+
+# ===== Functions =====
+
+def close(fd: SupportsIndex, /) -> None: ...
+def dup(fd: SupportsIndex, /) -> int: ...
+
+# the 5th tuple item is an address
+def getaddrinfo(
+    host: bytes | str | None,
+    port: bytes | str | int | None,
+    family: int = ...,
+    type: int = ...,
+    proto: int = ...,
+    flags: int = ...,
+) -> list[tuple[int, int, int, str, tuple[str, int] | tuple[str, int, int, int]]]: ...
+def gethostbyname(hostname: str, /) -> str: ...
+def gethostbyname_ex(hostname: str, /) -> tuple[str, list[str], list[str]]: ...
+def gethostname() -> str: ...
+def gethostbyaddr(ip_address: str, /) -> tuple[str, list[str], list[str]]: ...
+def getnameinfo(sockaddr: tuple[str, int] | tuple[str, int, int, int], flags: int, /) -> tuple[str, str]: ...
+def getprotobyname(protocolname: str, /) -> int: ...
+def getservbyname(servicename: str, protocolname: str = ..., /) -> int: ...
+def getservbyport(port: int, protocolname: str = ..., /) -> str: ...
+def ntohl(x: int, /) -> int: ...  # param & ret val are 32-bit ints
+def ntohs(x: int, /) -> int: ...  # param & ret val are 16-bit ints
+def htonl(x: int, /) -> int: ...  # param & ret val are 32-bit ints
+def htons(x: int, /) -> int: ...  # param & ret val are 16-bit ints
+def inet_aton(ip_addr: str, /) -> bytes: ...  # ret val 4 bytes in length
+def inet_ntoa(packed_ip: ReadableBuffer, /) -> str: ...
+def inet_pton(address_family: int, ip_string: str, /) -> bytes: ...
+def inet_ntop(address_family: int, packed_ip: ReadableBuffer, /) -> str: ...
+def getdefaulttimeout() -> float | None: ...
+def setdefaulttimeout(timeout: float | None, /) -> None: ...
+
+if sys.platform != "win32":
+    def sethostname(name: str, /) -> None: ...
+    def CMSG_LEN(length: int, /) -> int: ...
+    def CMSG_SPACE(length: int, /) -> int: ...
+    def socketpair(family: int = ..., type: int = ..., proto: int = ..., /) -> tuple[socket, socket]: ...
+
+def if_nameindex() -> list[tuple[int, str]]: ...
+def if_nametoindex(oname: str, /) -> int: ...
+def if_indextoname(index: int, /) -> str: ...
+
+CAPI: object

crates/red_knot/vendor/typeshed/stdlib/_stat.pyi

@@ -0,0 +1,117 @@
+import sys
+from typing import Literal
+
+SF_APPEND: Literal[0x00040000]
+SF_ARCHIVED: Literal[0x00010000]
+SF_IMMUTABLE: Literal[0x00020000]
+SF_NOUNLINK: Literal[0x00100000]
+SF_SNAPSHOT: Literal[0x00200000]
+
+ST_MODE: Literal[0]
+ST_INO: Literal[1]
+ST_DEV: Literal[2]
+ST_NLINK: Literal[3]
+ST_UID: Literal[4]
+ST_GID: Literal[5]
+ST_SIZE: Literal[6]
+ST_ATIME: Literal[7]
+ST_MTIME: Literal[8]
+ST_CTIME: Literal[9]
+
+S_IFIFO: Literal[0o010000]
+S_IFLNK: Literal[0o120000]
+S_IFREG: Literal[0o100000]
+S_IFSOCK: Literal[0o140000]
+S_IFBLK: Literal[0o060000]
+S_IFCHR: Literal[0o020000]
+S_IFDIR: Literal[0o040000]
+
+# These are 0 on systems that don't support the specific kind of file.
+# Example: Linux doesn't support door files, so S_IFDOOR is 0 on linux.
+S_IFDOOR: int
+S_IFPORT: int
+S_IFWHT: int
+
+S_ISUID: Literal[0o4000]
+S_ISGID: Literal[0o2000]
+S_ISVTX: Literal[0o1000]
+
+S_IRWXU: Literal[0o0700]
+S_IRUSR: Literal[0o0400]
+S_IWUSR: Literal[0o0200]
+S_IXUSR: Literal[0o0100]
+
+S_IRWXG: Literal[0o0070]
+S_IRGRP: Literal[0o0040]
+S_IWGRP: Literal[0o0020]
+S_IXGRP: Literal[0o0010]
+
+S_IRWXO: Literal[0o0007]
+S_IROTH: Literal[0o0004]
+S_IWOTH: Literal[0o0002]
+S_IXOTH: Literal[0o0001]
+
+S_ENFMT: Literal[0o2000]
+S_IREAD: Literal[0o0400]
+S_IWRITE: Literal[0o0200]
+S_IEXEC: Literal[0o0100]
+
+UF_APPEND: Literal[0x00000004]
+UF_COMPRESSED: Literal[0x00000020]  # OS X 10.6+ only
+UF_HIDDEN: Literal[0x00008000]  # OX X 10.5+ only
+UF_IMMUTABLE: Literal[0x00000002]
+UF_NODUMP: Literal[0x00000001]
+UF_NOUNLINK: Literal[0x00000010]
+UF_OPAQUE: Literal[0x00000008]
+
+def S_IMODE(mode: int, /) -> int: ...
+def S_IFMT(mode: int, /) -> int: ...
+def S_ISBLK(mode: int, /) -> bool: ...
+def S_ISCHR(mode: int, /) -> bool: ...
+def S_ISDIR(mode: int, /) -> bool: ...
+def S_ISDOOR(mode: int, /) -> bool: ...
+def S_ISFIFO(mode: int, /) -> bool: ...
+def S_ISLNK(mode: int, /) -> bool: ...
+def S_ISPORT(mode: int, /) -> bool: ...
+def S_ISREG(mode: int, /) -> bool: ...
+def S_ISSOCK(mode: int, /) -> bool: ...
+def S_ISWHT(mode: int, /) -> bool: ...
+def filemode(mode: int, /) -> str: ...
+
+if sys.platform == "win32":
+    IO_REPARSE_TAG_SYMLINK: int
+    IO_REPARSE_TAG_MOUNT_POINT: int
+    IO_REPARSE_TAG_APPEXECLINK: int
+
+if sys.platform == "win32":
+    FILE_ATTRIBUTE_ARCHIVE: Literal[32]
+    FILE_ATTRIBUTE_COMPRESSED: Literal[2048]
+    FILE_ATTRIBUTE_DEVICE: Literal[64]
+    FILE_ATTRIBUTE_DIRECTORY: Literal[16]
+    FILE_ATTRIBUTE_ENCRYPTED: Literal[16384]
+    FILE_ATTRIBUTE_HIDDEN: Literal[2]
+    FILE_ATTRIBUTE_INTEGRITY_STREAM: Literal[32768]
+    FILE_ATTRIBUTE_NORMAL: Literal[128]
+    FILE_ATTRIBUTE_NOT_CONTENT_INDEXED: Literal[8192]
+    FILE_ATTRIBUTE_NO_SCRUB_DATA: Literal[131072]
+    FILE_ATTRIBUTE_OFFLINE: Literal[4096]
+    FILE_ATTRIBUTE_READONLY: Literal[1]
+    FILE_ATTRIBUTE_REPARSE_POINT: Literal[1024]
+    FILE_ATTRIBUTE_SPARSE_FILE: Literal[512]
+    FILE_ATTRIBUTE_SYSTEM: Literal[4]
+    FILE_ATTRIBUTE_TEMPORARY: Literal[256]
+    FILE_ATTRIBUTE_VIRTUAL: Literal[65536]
+
+if sys.version_info >= (3, 13):
+    SF_SETTABLE: Literal[0x3FFF0000]
+    # https://github.com/python/cpython/issues/114081#issuecomment-2119017790
+    # SF_RESTRICTED: Literal[0x00080000]
+    SF_FIRMLINK: Literal[0x00800000]
+    SF_DATALESS: Literal[0x40000000]
+
+    SF_SUPPORTED: Literal[0x9F0000]
+    SF_SYNTHETIC: Literal[0xC0000000]
+
+    UF_TRACKED: Literal[0x00000040]
+    UF_DATAVAULT: Literal[0x00000080]
+    UF_SETTABLE: Literal[0x0000FFFF]

crates/red_knot/vendor/typeshed/stdlib/_thread.pyi

@@ -0,0 +1,59 @@
+import sys
+from _typeshed import structseq
+from collections.abc import Callable
+from threading import Thread
+from types import TracebackType
+from typing import Any, Final, NoReturn, final, overload
+from typing_extensions import TypeVarTuple, Unpack
+
+_Ts = TypeVarTuple("_Ts")
+
+error = RuntimeError
+
+def _count() -> int: ...
+@final
+class LockType:
+    def acquire(self, blocking: bool = ..., timeout: float = ...) -> bool: ...
+    def release(self) -> None: ...
+    def locked(self) -> bool: ...
+    def __enter__(self) -> bool: ...
+    def __exit__(
+        self, type: type[BaseException] | None, value: BaseException | None, traceback: TracebackType | None
+    ) -> None: ...
+
+@overload
+def start_new_thread(function: Callable[[Unpack[_Ts]], object], args: tuple[Unpack[_Ts]]) -> int: ...
+@overload
+def start_new_thread(function: Callable[..., object], args: tuple[Any, ...], kwargs: dict[str, Any]) -> int: ...
+def interrupt_main() -> None: ...
+def exit() -> NoReturn: ...
+def allocate_lock() -> LockType: ...
+def get_ident() -> int: ...
+def stack_size(size: int = ...) -> int: ...
+
+TIMEOUT_MAX: float
+
+def get_native_id() -> int: ...  # only available on some platforms
+@final
+class _ExceptHookArgs(structseq[Any], tuple[type[BaseException], BaseException | None, TracebackType | None, Thread | None]):
+    if sys.version_info >= (3, 10):
+        __match_args__: Final = ("exc_type", "exc_value", "exc_traceback", "thread")
+
+    @property
+    def exc_type(self) -> type[BaseException]: ...
+    @property
+    def exc_value(self) -> BaseException | None: ...
+    @property
+    def exc_traceback(self) -> TracebackType | None: ...
+    @property
+    def thread(self) -> Thread | None: ...
+
+_excepthook: Callable[[_ExceptHookArgs], Any]
+
+if sys.version_info >= (3, 12):
+    def daemon_threads_allowed() -> bool: ...
+
+class _local:
+    def __getattribute__(self, name: str, /) -> Any: ...
+    def __setattr__(self, name: str, value: Any, /) -> None: ...
+    def __delattr__(self, name: str, /) -> None: ...

crates/red_knot/vendor/typeshed/stdlib/_threading_local.pyi

@@ -0,0 +1,17 @@
+from typing import Any
+from typing_extensions import TypeAlias
+from weakref import ReferenceType
+
+__all__ = ["local"]
+_LocalDict: TypeAlias = dict[Any, Any]
+
+class _localimpl:
+    key: str
+    dicts: dict[int, tuple[ReferenceType[Any], _LocalDict]]
+    def get_dict(self) -> _LocalDict: ...
+    def create_dict(self) -> _LocalDict: ...
+
+class local:
+    def __getattribute__(self, name: str) -> Any: ...
+    def __setattr__(self, name: str, value: Any) -> None: ...
+    def __delattr__(self, name: str) -> None: ...

crates/red_knot/vendor/typeshed/stdlib/_tkinter.pyi

@@ -0,0 +1,121 @@
+import sys
+from typing import Any, ClassVar, Literal, final
+
+# _tkinter is meant to be only used internally by tkinter, but some tkinter
+# functions e.g. return _tkinter.Tcl_Obj objects. Tcl_Obj represents a Tcl
+# object that hasn't been converted to a string.
+#
+# There are not many ways to get Tcl_Objs from tkinter, and I'm not sure if the
+# only existing ways are supposed to return Tcl_Objs as opposed to returning
+# strings. Here's one of these things that return Tcl_Objs:
+#
+#    >>> import tkinter
+#    >>> text = tkinter.Text()
+#    >>> text.tag_add('foo', '1.0', 'end')
+#    >>> text.tag_ranges('foo')
+#    (<textindex object: '1.0'>, <textindex object: '2.0'>)
+@final
+class Tcl_Obj:
+    @property
+    def string(self) -> str: ...
+    @property
+    def typename(self) -> str: ...
+    __hash__: ClassVar[None]  # type: ignore[assignment]
+    def __eq__(self, value, /): ...
+    def __ge__(self, value, /): ...
+    def __gt__(self, value, /): ...
+    def __le__(self, value, /): ...
+    def __lt__(self, value, /): ...
+    def __ne__(self, value, /): ...
+
+class TclError(Exception): ...
+
+# This class allows running Tcl code. Tkinter uses it internally a lot, and
+# it's often handy to drop a piece of Tcl code into a tkinter program. Example:
+#
+#    >>> import tkinter, _tkinter
+#    >>> tkapp = tkinter.Tk().tk
+#    >>> isinstance(tkapp, _tkinter.TkappType)
+#    True
+#    >>> tkapp.call('set', 'foo', (1,2,3))
+#    (1, 2, 3)
+#    >>> tkapp.eval('return $foo')
+#    '1 2 3'
+#    >>>
+#
+# call args can be pretty much anything. Also, call(some_tuple) is same as call(*some_tuple).
+#
+# eval always returns str because _tkinter_tkapp_eval_impl in _tkinter.c calls
+# Tkapp_UnicodeResult, and it returns a string when it succeeds.
+@final
+class TkappType:
+    # Please keep in sync with tkinter.Tk
+    def adderrorinfo(self, msg, /): ...
+    def call(self, command: Any, /, *args: Any) -> Any: ...
+    def createcommand(self, name, func, /): ...
+    if sys.platform != "win32":
+        def createfilehandler(self, file, mask, func, /): ...
+        def deletefilehandler(self, file, /): ...
+
+    def createtimerhandler(self, milliseconds, func, /): ...
+    def deletecommand(self, name, /): ...
+    def dooneevent(self, flags: int = 0, /): ...
+    def eval(self, script: str, /) -> str: ...
+    def evalfile(self, fileName, /): ...
+    def exprboolean(self, s, /): ...
+    def exprdouble(self, s, /): ...
+    def exprlong(self, s, /): ...
+    def exprstring(self, s, /): ...
+    def getboolean(self, arg, /): ...
+    def getdouble(self, arg, /): ...
+    def getint(self, arg, /): ...
+    def getvar(self, *args, **kwargs): ...
+    def globalgetvar(self, *args, **kwargs): ...
+    def globalsetvar(self, *args, **kwargs): ...
+    def globalunsetvar(self, *args, **kwargs): ...
+    def interpaddr(self): ...
+    def loadtk(self) -> None: ...
+    def mainloop(self, threshold: int = 0, /): ...
+    def quit(self): ...
+    def record(self, script, /): ...
+    def setvar(self, *ags, **kwargs): ...
+    if sys.version_info < (3, 11):
+        def split(self, arg, /): ...
+
+    def splitlist(self, arg, /): ...
+    def unsetvar(self, *args, **kwargs): ...
+    def wantobjects(self, *args, **kwargs): ...
+    def willdispatch(self): ...
+
+# These should be kept in sync with tkinter.tix constants, except ALL_EVENTS which doesn't match TCL_ALL_EVENTS
+ALL_EVENTS: Literal[-3]
+FILE_EVENTS: Literal[8]
+IDLE_EVENTS: Literal[32]
+TIMER_EVENTS: Literal[16]
+WINDOW_EVENTS: Literal[4]
+
+DONT_WAIT: Literal[2]
+EXCEPTION: Literal[8]
+READABLE: Literal[2]
+WRITABLE: Literal[4]
+
+TCL_VERSION: str
+TK_VERSION: str
+
+@final
+class TkttType:
+    def deletetimerhandler(self): ...
+
+def create(
+    screenName: str | None = None,
+    baseName: str = "",
+    className: str = "Tk",
+    interactive: bool = False,
+    wantobjects: bool = False,
+    wantTk: bool = True,
+    sync: bool = False,
+    use: str | None = None,
+    /,
+): ...
+def getbusywaitinterval(): ...
+def setbusywaitinterval(new_val, /): ...

crates/red_knot/vendor/typeshed/stdlib/_tracemalloc.pyi

@@ -0,0 +1,17 @@
+import sys
+from collections.abc import Sequence
+from tracemalloc import _FrameTuple, _TraceTuple
+
+def _get_object_traceback(obj: object, /) -> Sequence[_FrameTuple] | None: ...
+def _get_traces() -> Sequence[_TraceTuple]: ...
+def clear_traces() -> None: ...
+def get_traceback_limit() -> int: ...
+def get_traced_memory() -> tuple[int, int]: ...
+def get_tracemalloc_memory() -> int: ...
+def is_tracing() -> bool: ...
+
+if sys.version_info >= (3, 9):
+    def reset_peak() -> None: ...
+
+def start(nframe: int = 1, /) -> None: ...
+def stop() -> None: ...

crates/red_knot/vendor/typeshed/stdlib/_typeshed/README.md

@@ -0,0 +1,34 @@
+# Utility types for typeshed
+
+This package and its submodules contains various common types used by
+typeshed. It can also be used by packages outside typeshed, but beware
+the API stability guarantees below.
+
+## Usage
+
+The `_typeshed` package and its types do not exist at runtime, but can be
+used freely in stubs (`.pyi`) files. To import the types from this package in
+implementation (`.py`) files, use the following construct:
+
+```python
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from _typeshed import ...
+```
+
+Types can then be used in annotations by either quoting them or
+using:
+
+```python
+from __future__ import annotations
+```
+
+## API Stability
+
+You can use this package and its submodules outside of typeshed, but we
+guarantee only limited API stability. Items marked as "stable" will not be
+removed or changed in an incompatible way for at least one year.
+Before making such a change, the "stable" moniker will be removed
+and we will mark the type in question as deprecated. No guarantees
+are made about unmarked types.

crates/red_knot/vendor/typeshed/stdlib/_typeshed/__init__.pyi

@@ -0,0 +1,363 @@
+# Utility types for typeshed
+#
+# See the README.md file in this directory for more information.
+
+import sys
+from collections.abc import Awaitable, Callable, Iterable, Sequence, Set as AbstractSet, Sized
+from dataclasses import Field
+from os import PathLike
+from types import FrameType, TracebackType
+from typing import (
+    Any,
+    AnyStr,
+    ClassVar,
+    Final,
+    Generic,
+    Literal,
+    Protocol,
+    SupportsFloat,
+    SupportsIndex,
+    SupportsInt,
+    TypeVar,
+    final,
+    overload,
+)
+from typing_extensions import Buffer, LiteralString, TypeAlias
+
+_KT = TypeVar("_KT")
+_KT_co = TypeVar("_KT_co", covariant=True)
+_KT_contra = TypeVar("_KT_contra", contravariant=True)
+_VT = TypeVar("_VT")
+_VT_co = TypeVar("_VT_co", covariant=True)
+_T = TypeVar("_T")
+_T_co = TypeVar("_T_co", covariant=True)
+_T_contra = TypeVar("_T_contra", contravariant=True)
+
+# Alternative to `typing_extensions.Self`, exclusively for use with `__new__`
+# in metaclasses:
+#     def __new__(cls: type[Self], ...) -> Self: ...
+# In other cases, use `typing_extensions.Self`.
+Self = TypeVar("Self")  # noqa: Y001
+
+# covariant version of typing.AnyStr, useful for protocols
+AnyStr_co = TypeVar("AnyStr_co", str, bytes, covariant=True)  # noqa: Y001
+
+# For partially known annotations. Usually, fields where type annotations
+# haven't been added are left unannotated, but in some situations this
+# isn't possible or a type is already partially known. In cases like these,
+# use Incomplete instead of Any as a marker. For example, use
+# "Incomplete | None" instead of "Any | None".
+Incomplete: TypeAlias = Any  # stable
+
+# To describe a function parameter that is unused and will work with anything.
+Unused: TypeAlias = object  # stable
+
+# Marker for return types that include None, but where forcing the user to
+# check for None can be detrimental. Sometimes called "the Any trick". See
+# CONTRIBUTING.md for more information.
+MaybeNone: TypeAlias = Any  # stable
+
+# Used to mark arguments that default to a sentinel value. This prevents
+# stubtest from complaining about the default value not matching.
+#
+# def foo(x: int | None = sentinel) -> None: ...
+#
+# In cases where the sentinel object is exported and can be used by user code,
+# a construct like this is better:
+#
+# _SentinelType = NewType("_SentinelType", object)
+# sentinel: _SentinelType
+# def foo(x: int | None | _SentinelType = ...) -> None: ...
+sentinel: Any
+
+# stable
+class IdentityFunction(Protocol):
+    def __call__(self, x: _T, /) -> _T: ...
+
+# stable
+class SupportsNext(Protocol[_T_co]):
+    def __next__(self) -> _T_co: ...
+
+# stable
+class SupportsAnext(Protocol[_T_co]):
+    def __anext__(self) -> Awaitable[_T_co]: ...
+
+# Comparison protocols
+
+class SupportsDunderLT(Protocol[_T_contra]):
+    def __lt__(self, other: _T_contra, /) -> bool: ...
+
+class SupportsDunderGT(Protocol[_T_contra]):
+    def __gt__(self, other: _T_contra, /) -> bool: ...
+
+class SupportsDunderLE(Protocol[_T_contra]):
+    def __le__(self, other: _T_contra, /) -> bool: ...
+
+class SupportsDunderGE(Protocol[_T_contra]):
+    def __ge__(self, other: _T_contra, /) -> bool: ...
+
+class SupportsAllComparisons(
+    SupportsDunderLT[Any], SupportsDunderGT[Any], SupportsDunderLE[Any], SupportsDunderGE[Any], Protocol
+): ...
+
+SupportsRichComparison: TypeAlias = SupportsDunderLT[Any] | SupportsDunderGT[Any]
+SupportsRichComparisonT = TypeVar("SupportsRichComparisonT", bound=SupportsRichComparison)  # noqa: Y001
+
+# Dunder protocols
+
+class SupportsAdd(Protocol[_T_contra, _T_co]):
+    def __add__(self, x: _T_contra, /) -> _T_co: ...
+
+class SupportsRAdd(Protocol[_T_contra, _T_co]):
+    def __radd__(self, x: _T_contra, /) -> _T_co: ...
+
+class SupportsSub(Protocol[_T_contra, _T_co]):
+    def __sub__(self, x: _T_contra, /) -> _T_co: ...
+
+class SupportsRSub(Protocol[_T_contra, _T_co]):
+    def __rsub__(self, x: _T_contra, /) -> _T_co: ...
+
+class SupportsDivMod(Protocol[_T_contra, _T_co]):
+    def __divmod__(self, other: _T_contra, /) -> _T_co: ...
+
+class SupportsRDivMod(Protocol[_T_contra, _T_co]):
+    def __rdivmod__(self, other: _T_contra, /) -> _T_co: ...
+
+# This protocol is generic over the iterator type, while Iterable is
+# generic over the type that is iterated over.
+class SupportsIter(Protocol[_T_co]):
+    def __iter__(self) -> _T_co: ...
+
+# This protocol is generic over the iterator type, while AsyncIterable is
+# generic over the type that is iterated over.
+class SupportsAiter(Protocol[_T_co]):
+    def __aiter__(self) -> _T_co: ...
+
+class SupportsLenAndGetItem(Protocol[_T_co]):
+    def __len__(self) -> int: ...
+    def __getitem__(self, k: int, /) -> _T_co: ...
+
+class SupportsTrunc(Protocol):
+    def __trunc__(self) -> int: ...
+
+# Mapping-like protocols
+
+# stable
+class SupportsItems(Protocol[_KT_co, _VT_co]):
+    def items(self) -> AbstractSet[tuple[_KT_co, _VT_co]]: ...
+
+# stable
+class SupportsKeysAndGetItem(Protocol[_KT, _VT_co]):
+    def keys(self) -> Iterable[_KT]: ...
+    def __getitem__(self, key: _KT, /) -> _VT_co: ...
+
+# This protocol is currently under discussion. Use SupportsContainsAndGetItem
+# instead, if you require the __contains__ method.
+# See https://github.com/python/typeshed/issues/11822.
+class SupportsGetItem(Protocol[_KT_contra, _VT_co]):
+    def __contains__(self, x: Any, /) -> bool: ...
+    def __getitem__(self, key: _KT_contra, /) -> _VT_co: ...
+
+# stable
+class SupportsContainsAndGetItem(Protocol[_KT_contra, _VT_co]):
+    def __contains__(self, x: Any, /) -> bool: ...
+    def __getitem__(self, key: _KT_contra, /) -> _VT_co: ...
+
+# stable
+class SupportsItemAccess(Protocol[_KT_contra, _VT]):
+    def __contains__(self, x: Any, /) -> bool: ...
+    def __getitem__(self, key: _KT_contra, /) -> _VT: ...
+    def __setitem__(self, key: _KT_contra, value: _VT, /) -> None: ...
+    def __delitem__(self, key: _KT_contra, /) -> None: ...
+
+StrPath: TypeAlias = str | PathLike[str]  # stable
+BytesPath: TypeAlias = bytes | PathLike[bytes]  # stable
+GenericPath: TypeAlias = AnyStr | PathLike[AnyStr]
+StrOrBytesPath: TypeAlias = str | bytes | PathLike[str] | PathLike[bytes]  # stable
+
+OpenTextModeUpdating: TypeAlias = Literal[
+    "r+",
+    "+r",
+    "rt+",
+    "r+t",
+    "+rt",
+    "tr+",
+    "t+r",
+    "+tr",
+    "w+",
+    "+w",
+    "wt+",
+    "w+t",
+    "+wt",
+    "tw+",
+    "t+w",
+    "+tw",
+    "a+",
+    "+a",
+    "at+",
+    "a+t",
+    "+at",
+    "ta+",
+    "t+a",
+    "+ta",
+    "x+",
+    "+x",
+    "xt+",
+    "x+t",
+    "+xt",
+    "tx+",
+    "t+x",
+    "+tx",
+]
+OpenTextModeWriting: TypeAlias = Literal["w", "wt", "tw", "a", "at", "ta", "x", "xt", "tx"]
+OpenTextModeReading: TypeAlias = Literal["r", "rt", "tr", "U", "rU", "Ur", "rtU", "rUt", "Urt", "trU", "tUr", "Utr"]
+OpenTextMode: TypeAlias = OpenTextModeUpdating | OpenTextModeWriting | OpenTextModeReading
+OpenBinaryModeUpdating: TypeAlias = Literal[
+    "rb+",
+    "r+b",
+    "+rb",
+    "br+",
+    "b+r",
+    "+br",
+    "wb+",
+    "w+b",
+    "+wb",
+    "bw+",
+    "b+w",
+    "+bw",
+    "ab+",
+    "a+b",
+    "+ab",
+    "ba+",
+    "b+a",
+    "+ba",
+    "xb+",
+    "x+b",
+    "+xb",
+    "bx+",
+    "b+x",
+    "+bx",
+]
+OpenBinaryModeWriting: TypeAlias = Literal["wb", "bw", "ab", "ba", "xb", "bx"]
+OpenBinaryModeReading: TypeAlias = Literal["rb", "br", "rbU", "rUb", "Urb", "brU", "bUr", "Ubr"]
+OpenBinaryMode: TypeAlias = OpenBinaryModeUpdating | OpenBinaryModeReading | OpenBinaryModeWriting
+
+# stable
+class HasFileno(Protocol):
+    def fileno(self) -> int: ...
+
+FileDescriptor: TypeAlias = int  # stable
+FileDescriptorLike: TypeAlias = int | HasFileno  # stable
+FileDescriptorOrPath: TypeAlias = int | StrOrBytesPath
+
+# stable
+class SupportsRead(Protocol[_T_co]):
+    def read(self, length: int = ..., /) -> _T_co: ...
+
+# stable
+class SupportsReadline(Protocol[_T_co]):
+    def readline(self, length: int = ..., /) -> _T_co: ...
+
+# stable
+class SupportsNoArgReadline(Protocol[_T_co]):
+    def readline(self) -> _T_co: ...
+
+# stable
+class SupportsWrite(Protocol[_T_contra]):
+    def write(self, s: _T_contra, /) -> object: ...
+
+# stable
+class SupportsFlush(Protocol):
+    def flush(self) -> object: ...
+
+# Unfortunately PEP 688 does not allow us to distinguish read-only
+# from writable buffers. We use these aliases for readability for now.
+# Perhaps a future extension of the buffer protocol will allow us to
+# distinguish these cases in the type system.
+ReadOnlyBuffer: TypeAlias = Buffer  # stable
+# Anything that implements the read-write buffer interface.
+WriteableBuffer: TypeAlias = Buffer
+# Same as WriteableBuffer, but also includes read-only buffer types (like bytes).
+ReadableBuffer: TypeAlias = Buffer  # stable
+
+class SliceableBuffer(Buffer, Protocol):
+    def __getitem__(self, slice: slice, /) -> Sequence[int]: ...
+
+class IndexableBuffer(Buffer, Protocol):
+    def __getitem__(self, i: int, /) -> int: ...
+
+class SupportsGetItemBuffer(SliceableBuffer, IndexableBuffer, Protocol):
+    def __contains__(self, x: Any, /) -> bool: ...
+    @overload
+    def __getitem__(self, slice: slice, /) -> Sequence[int]: ...
+    @overload
+    def __getitem__(self, i: int, /) -> int: ...
+
+class SizedBuffer(Sized, Buffer, Protocol): ...
+
+# for compatibility with third-party stubs that may use this
+_BufferWithLen: TypeAlias = SizedBuffer  # not stable  # noqa: Y047
+
+ExcInfo: TypeAlias = tuple[type[BaseException], BaseException, TracebackType]
+OptExcInfo: TypeAlias = ExcInfo | tuple[None, None, None]
+
+# stable
+if sys.version_info >= (3, 10):
+    from types import NoneType as NoneType
+else:
+    # Used by type checkers for checks involving None (does not exist at runtime)
+    @final
+    class NoneType:
+        def __bool__(self) -> Literal[False]: ...
+
+# This is an internal CPython type that is like, but subtly different from, a NamedTuple
+# Subclasses of this type are found in multiple modules.
+# In typeshed, `structseq` is only ever used as a mixin in combination with a fixed-length `Tuple`
+# See discussion at #6546 & #6560
+# `structseq` classes are unsubclassable, so are all decorated with `@final`.
+class structseq(Generic[_T_co]):
+    n_fields: Final[int]
+    n_unnamed_fields: Final[int]
+    n_sequence_fields: Final[int]
+    # The first parameter will generally only take an iterable of a specific length.
+    # E.g. `os.uname_result` takes any iterable of length exactly 5.
+    #
+    # The second parameter will accept a dict of any kind without raising an exception,
+    # but only has any meaning if you supply it a dict where the keys are strings.
+    # https://github.com/python/typeshed/pull/6560#discussion_r767149830
+    def __new__(cls: type[Self], sequence: Iterable[_T_co], dict: dict[str, Any] = ...) -> Self: ...
+    if sys.version_info >= (3, 13):
+        def __replace__(self: Self, **kwargs: Any) -> Self: ...
+
+# Superset of typing.AnyStr that also includes LiteralString
+AnyOrLiteralStr = TypeVar("AnyOrLiteralStr", str, bytes, LiteralString)  # noqa: Y001
+
+# Represents when str or LiteralStr is acceptable. Useful for string processing
+# APIs where literalness of return value depends on literalness of inputs
+StrOrLiteralStr = TypeVar("StrOrLiteralStr", LiteralString, str)  # noqa: Y001
+
+# Objects suitable to be passed to sys.setprofile, threading.setprofile, and similar
+ProfileFunction: TypeAlias = Callable[[FrameType, str, Any], object]
+
+# Objects suitable to be passed to sys.settrace, threading.settrace, and similar
+TraceFunction: TypeAlias = Callable[[FrameType, str, Any], TraceFunction | None]
+
+# experimental
+# Might not work as expected for pyright, see
+#   https://github.com/python/typeshed/pull/9362
+#   https://github.com/microsoft/pyright/issues/4339
+class DataclassInstance(Protocol):
+    __dataclass_fields__: ClassVar[dict[str, Field[Any]]]
+
+# Anything that can be passed to the int/float constructors
+ConvertibleToInt: TypeAlias = str | ReadableBuffer | SupportsInt | SupportsIndex | SupportsTrunc
+ConvertibleToFloat: TypeAlias = str | ReadableBuffer | SupportsFloat | SupportsIndex
+
+# A few classes updated from Foo(str, Enum) to Foo(StrEnum). This is a convenience so these
+# can be accurate on all python versions without getting too wordy
+if sys.version_info >= (3, 11):
+    from enum import StrEnum as StrEnum
+else:
+    from enum import Enum
+
+    class StrEnum(str, Enum): ...

crates/red_knot/vendor/typeshed/stdlib/_typeshed/dbapi.pyi

@@ -0,0 +1,37 @@
+# PEP 249 Database API 2.0 Types
+# https://www.python.org/dev/peps/pep-0249/
+
+from collections.abc import Mapping, Sequence
+from typing import Any, Protocol
+from typing_extensions import TypeAlias
+
+DBAPITypeCode: TypeAlias = Any | None
+# Strictly speaking, this should be a Sequence, but the type system does
+# not support fixed-length sequences.
+DBAPIColumnDescription: TypeAlias = tuple[str, DBAPITypeCode, int | None, int | None, int | None, int | None, bool | None]
+
+class DBAPIConnection(Protocol):
+    def close(self) -> object: ...
+    def commit(self) -> object: ...
+    # optional:
+    # def rollback(self) -> Any: ...
+    def cursor(self) -> DBAPICursor: ...
+
+class DBAPICursor(Protocol):
+    @property
+    def description(self) -> Sequence[DBAPIColumnDescription] | None: ...
+    @property
+    def rowcount(self) -> int: ...
+    # optional:
+    # def callproc(self, procname: str, parameters: Sequence[Any] = ..., /) -> Sequence[Any]: ...
+    def close(self) -> object: ...
+    def execute(self, operation: str, parameters: Sequence[Any] | Mapping[str, Any] = ..., /) -> object: ...
+    def executemany(self, operation: str, seq_of_parameters: Sequence[Sequence[Any]], /) -> object: ...
+    def fetchone(self) -> Sequence[Any] | None: ...
+    def fetchmany(self, size: int = ..., /) -> Sequence[Sequence[Any]]: ...
+    def fetchall(self) -> Sequence[Sequence[Any]]: ...
+    # optional:
+    # def nextset(self) -> None | Literal[True]: ...
+    arraysize: int
+    def setinputsizes(self, sizes: Sequence[DBAPITypeCode | int | None], /) -> object: ...
+    def setoutputsize(self, size: int, column: int = ..., /) -> object: ...

crates/red_knot/vendor/typeshed/stdlib/_typeshed/importlib.pyi

@@ -0,0 +1,18 @@
+# Implicit protocols used in importlib.
+# We intentionally omit deprecated and optional methods.
+
+from collections.abc import Sequence
+from importlib.machinery import ModuleSpec
+from types import ModuleType
+from typing import Protocol
+
+__all__ = ["LoaderProtocol", "MetaPathFinderProtocol", "PathEntryFinderProtocol"]
+
+class LoaderProtocol(Protocol):
+    def load_module(self, fullname: str, /) -> ModuleType: ...
+
+class MetaPathFinderProtocol(Protocol):
+    def find_spec(self, fullname: str, path: Sequence[str] | None, target: ModuleType | None = ..., /) -> ModuleSpec | None: ...
+
+class PathEntryFinderProtocol(Protocol):
+    def find_spec(self, fullname: str, target: ModuleType | None = ..., /) -> ModuleSpec | None: ...

crates/red_knot/vendor/typeshed/stdlib/_typeshed/wsgi.pyi

@@ -0,0 +1,44 @@
+# Types to support PEP 3333 (WSGI)
+#
+# Obsolete since Python 3.11: Use wsgiref.types instead.
+#
+# See the README.md file in this directory for more information.
+
+import sys
+from _typeshed import OptExcInfo
+from collections.abc import Callable, Iterable, Iterator
+from typing import Any, Protocol
+from typing_extensions import TypeAlias
+
+class _Readable(Protocol):
+    def read(self, size: int = ..., /) -> bytes: ...
+    # Optional: def close(self) -> object: ...
+
+if sys.version_info >= (3, 11):
+    from wsgiref.types import *
+else:
+    # stable
+    class StartResponse(Protocol):
+        def __call__(
+            self, status: str, headers: list[tuple[str, str]], exc_info: OptExcInfo | None = ..., /
+        ) -> Callable[[bytes], object]: ...
+
+    WSGIEnvironment: TypeAlias = dict[str, Any]  # stable
+    WSGIApplication: TypeAlias = Callable[[WSGIEnvironment, StartResponse], Iterable[bytes]]  # stable
+
+    # WSGI input streams per PEP 3333, stable
+    class InputStream(Protocol):
+        def read(self, size: int = ..., /) -> bytes: ...
+        def readline(self, size: int = ..., /) -> bytes: ...
+        def readlines(self, hint: int = ..., /) -> list[bytes]: ...
+        def __iter__(self) -> Iterator[bytes]: ...
+
+    # WSGI error streams per PEP 3333, stable
+    class ErrorStream(Protocol):
+        def flush(self) -> object: ...
+        def write(self, s: str, /) -> object: ...
+        def writelines(self, seq: list[str], /) -> object: ...
+
+    # Optional file wrapper in wsgi.file_wrapper
+    class FileWrapper(Protocol):
+        def __call__(self, file: _Readable, block_size: int = ..., /) -> Iterable[bytes]: ...

crates/red_knot/vendor/typeshed/stdlib/_typeshed/xml.pyi

@@ -0,0 +1,9 @@
+# See the README.md file in this directory for more information.
+
+from typing import Any, Protocol
+
+# As defined https://docs.python.org/3/library/xml.dom.html#domimplementation-objects
+class DOMImplementation(Protocol):
+    def hasFeature(self, feature: str, version: str | None, /) -> bool: ...
+    def createDocument(self, namespaceUri: str, qualifiedName: str, doctype: Any | None, /) -> Any: ...
+    def createDocumentType(self, qualifiedName: str, publicId: str, systemId: str, /) -> Any: ...

crates/red_knot/vendor/typeshed/stdlib/_warnings.pyi

@@ -0,0 +1,55 @@
+import sys
+from typing import Any, overload
+
+_defaultaction: str
+_onceregistry: dict[Any, Any]
+filters: list[tuple[str, str | None, type[Warning], str | None, int]]
+
+if sys.version_info >= (3, 12):
+    @overload
+    def warn(
+        message: str,
+        category: type[Warning] | None = None,
+        stacklevel: int = 1,
+        source: Any | None = None,
+        *,
+        skip_file_prefixes: tuple[str, ...] = (),
+    ) -> None: ...
+    @overload
+    def warn(
+        message: Warning,
+        category: Any = None,
+        stacklevel: int = 1,
+        source: Any | None = None,
+        *,
+        skip_file_prefixes: tuple[str, ...] = (),
+    ) -> None: ...
+
+else:
+    @overload
+    def warn(message: str, category: type[Warning] | None = None, stacklevel: int = 1, source: Any | None = None) -> None: ...
+    @overload
+    def warn(message: Warning, category: Any = None, stacklevel: int = 1, source: Any | None = None) -> None: ...
+
+@overload
+def warn_explicit(
+    message: str,
+    category: type[Warning],
+    filename: str,
+    lineno: int,
+    module: str | None = ...,
+    registry: dict[str | tuple[str, type[Warning], int], int] | None = ...,
+    module_globals: dict[str, Any] | None = ...,
+    source: Any | None = ...,
+) -> None: ...
+@overload
+def warn_explicit(
+    message: Warning,
+    category: Any,
+    filename: str,
+    lineno: int,
+    module: str | None = ...,
+    registry: dict[str | tuple[str, type[Warning], int], int] | None = ...,
+    module_globals: dict[str, Any] | None = ...,
+    source: Any | None = ...,
+) -> None: ...

crates/red_knot/vendor/typeshed/stdlib/_weakref.pyi

@@ -0,0 +1,41 @@
+import sys
+from collections.abc import Callable
+from typing import Any, Generic, TypeVar, final, overload
+from typing_extensions import Self
+
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
+_C = TypeVar("_C", bound=Callable[..., Any])
+_T = TypeVar("_T")
+
+@final
+class CallableProxyType(Generic[_C]):  # "weakcallableproxy"
+    def __eq__(self, value: object, /) -> bool: ...
+    def __getattr__(self, attr: str) -> Any: ...
+    __call__: _C
+
+@final
+class ProxyType(Generic[_T]):  # "weakproxy"
+    def __eq__(self, value: object, /) -> bool: ...
+    def __getattr__(self, attr: str) -> Any: ...
+
+class ReferenceType(Generic[_T]):
+    __callback__: Callable[[ReferenceType[_T]], Any]
+    def __new__(cls, o: _T, callback: Callable[[ReferenceType[_T]], Any] | None = ..., /) -> Self: ...
+    def __call__(self) -> _T | None: ...
+    def __eq__(self, value: object, /) -> bool: ...
+    def __hash__(self) -> int: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
+
+ref = ReferenceType
+
+def getweakrefcount(object: Any, /) -> int: ...
+def getweakrefs(object: Any, /) -> list[Any]: ...
+
+# Return CallableProxyType if object is callable, ProxyType otherwise
+@overload
+def proxy(object: _C, callback: Callable[[_C], Any] | None = None, /) -> CallableProxyType[_C]: ...
+@overload
+def proxy(object: _T, callback: Callable[[_T], Any] | None = None, /) -> Any: ...

crates/red_knot/vendor/typeshed/stdlib/_weakrefset.pyi

@@ -0,0 +1,51 @@
+import sys
+from collections.abc import Iterable, Iterator, MutableSet
+from typing import Any, TypeVar, overload
+from typing_extensions import Self
+
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
+__all__ = ["WeakSet"]
+
+_S = TypeVar("_S")
+_T = TypeVar("_T")
+
+class WeakSet(MutableSet[_T]):
+    @overload
+    def __init__(self, data: None = None) -> None: ...
+    @overload
+    def __init__(self, data: Iterable[_T]) -> None: ...
+    def add(self, item: _T) -> None: ...
+    def discard(self, item: _T) -> None: ...
+    def copy(self) -> Self: ...
+    def remove(self, item: _T) -> None: ...
+    def update(self, other: Iterable[_T]) -> None: ...
+    def __contains__(self, item: object) -> bool: ...
+    def __len__(self) -> int: ...
+    def __iter__(self) -> Iterator[_T]: ...
+    def __ior__(self, other: Iterable[_T]) -> Self: ...  # type: ignore[override,misc]
+    def difference(self, other: Iterable[_T]) -> Self: ...
+    def __sub__(self, other: Iterable[Any]) -> Self: ...
+    def difference_update(self, other: Iterable[Any]) -> None: ...
+    def __isub__(self, other: Iterable[Any]) -> Self: ...
+    def intersection(self, other: Iterable[_T]) -> Self: ...
+    def __and__(self, other: Iterable[Any]) -> Self: ...
+    def intersection_update(self, other: Iterable[Any]) -> None: ...
+    def __iand__(self, other: Iterable[Any]) -> Self: ...
+    def issubset(self, other: Iterable[_T]) -> bool: ...
+    def __le__(self, other: Iterable[_T]) -> bool: ...
+    def __lt__(self, other: Iterable[_T]) -> bool: ...
+    def issuperset(self, other: Iterable[_T]) -> bool: ...
+    def __ge__(self, other: Iterable[_T]) -> bool: ...
+    def __gt__(self, other: Iterable[_T]) -> bool: ...
+    def __eq__(self, other: object) -> bool: ...
+    def symmetric_difference(self, other: Iterable[_S]) -> WeakSet[_S | _T]: ...
+    def __xor__(self, other: Iterable[_S]) -> WeakSet[_S | _T]: ...
+    def symmetric_difference_update(self, other: Iterable[_T]) -> None: ...
+    def __ixor__(self, other: Iterable[_T]) -> Self: ...  # type: ignore[override,misc]
+    def union(self, other: Iterable[_S]) -> WeakSet[_S | _T]: ...
+    def __or__(self, other: Iterable[_S]) -> WeakSet[_S | _T]: ...
+    def isdisjoint(self, other: Iterable[_T]) -> bool: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...

crates/red_knot/vendor/typeshed/stdlib/_winapi.pyi

@@ -0,0 +1,255 @@
+import sys
+from _typeshed import ReadableBuffer
+from collections.abc import Sequence
+from typing import Any, Literal, NoReturn, final, overload
+
+if sys.platform == "win32":
+    ABOVE_NORMAL_PRIORITY_CLASS: Literal[0x8000]
+    BELOW_NORMAL_PRIORITY_CLASS: Literal[0x4000]
+
+    CREATE_BREAKAWAY_FROM_JOB: Literal[0x1000000]
+    CREATE_DEFAULT_ERROR_MODE: Literal[0x4000000]
+    CREATE_NO_WINDOW: Literal[0x8000000]
+    CREATE_NEW_CONSOLE: Literal[0x10]
+    CREATE_NEW_PROCESS_GROUP: Literal[0x200]
+
+    DETACHED_PROCESS: Literal[8]
+    DUPLICATE_CLOSE_SOURCE: Literal[1]
+    DUPLICATE_SAME_ACCESS: Literal[2]
+
+    ERROR_ALREADY_EXISTS: Literal[183]
+    ERROR_BROKEN_PIPE: Literal[109]
+    ERROR_IO_PENDING: Literal[997]
+    ERROR_MORE_DATA: Literal[234]
+    ERROR_NETNAME_DELETED: Literal[64]
+    ERROR_NO_DATA: Literal[232]
+    ERROR_NO_SYSTEM_RESOURCES: Literal[1450]
+    ERROR_OPERATION_ABORTED: Literal[995]
+    ERROR_PIPE_BUSY: Literal[231]
+    ERROR_PIPE_CONNECTED: Literal[535]
+    ERROR_SEM_TIMEOUT: Literal[121]
+
+    FILE_FLAG_FIRST_PIPE_INSTANCE: Literal[0x80000]
+    FILE_FLAG_OVERLAPPED: Literal[0x40000000]
+
+    FILE_GENERIC_READ: Literal[1179785]
+    FILE_GENERIC_WRITE: Literal[1179926]
+
+    FILE_MAP_ALL_ACCESS: Literal[983071]
+    FILE_MAP_COPY: Literal[1]
+    FILE_MAP_EXECUTE: Literal[32]
+    FILE_MAP_READ: Literal[4]
+    FILE_MAP_WRITE: Literal[2]
+
+    FILE_TYPE_CHAR: Literal[2]
+    FILE_TYPE_DISK: Literal[1]
+    FILE_TYPE_PIPE: Literal[3]
+    FILE_TYPE_REMOTE: Literal[32768]
+    FILE_TYPE_UNKNOWN: Literal[0]
+
+    GENERIC_READ: Literal[0x80000000]
+    GENERIC_WRITE: Literal[0x40000000]
+    HIGH_PRIORITY_CLASS: Literal[0x80]
+    INFINITE: Literal[0xFFFFFFFF]
+    # Ignore the Flake8 error -- flake8-pyi assumes
+    # most numbers this long will be implementation details,
+    # but here we can see that it's a power of 2
+    INVALID_HANDLE_VALUE: Literal[0xFFFFFFFFFFFFFFFF]  # noqa: Y054
+    IDLE_PRIORITY_CLASS: Literal[0x40]
+    NORMAL_PRIORITY_CLASS: Literal[0x20]
+    REALTIME_PRIORITY_CLASS: Literal[0x100]
+    NMPWAIT_WAIT_FOREVER: Literal[0xFFFFFFFF]
+
+    MEM_COMMIT: Literal[0x1000]
+    MEM_FREE: Literal[0x10000]
+    MEM_IMAGE: Literal[0x1000000]
+    MEM_MAPPED: Literal[0x40000]
+    MEM_PRIVATE: Literal[0x20000]
+    MEM_RESERVE: Literal[0x2000]
+
+    NULL: Literal[0]
+    OPEN_EXISTING: Literal[3]
+
+    PIPE_ACCESS_DUPLEX: Literal[3]
+    PIPE_ACCESS_INBOUND: Literal[1]
+    PIPE_READMODE_MESSAGE: Literal[2]
+    PIPE_TYPE_MESSAGE: Literal[4]
+    PIPE_UNLIMITED_INSTANCES: Literal[255]
+    PIPE_WAIT: Literal[0]
+
+    PAGE_EXECUTE: Literal[0x10]
+    PAGE_EXECUTE_READ: Literal[0x20]
+    PAGE_EXECUTE_READWRITE: Literal[0x40]
+    PAGE_EXECUTE_WRITECOPY: Literal[0x80]
+    PAGE_GUARD: Literal[0x100]
+    PAGE_NOACCESS: Literal[0x1]
+    PAGE_NOCACHE: Literal[0x200]
+    PAGE_READONLY: Literal[0x2]
+    PAGE_READWRITE: Literal[0x4]
+    PAGE_WRITECOMBINE: Literal[0x400]
+    PAGE_WRITECOPY: Literal[0x8]
+
+    PROCESS_ALL_ACCESS: Literal[0x1FFFFF]
+    PROCESS_DUP_HANDLE: Literal[0x40]
+
+    SEC_COMMIT: Literal[0x8000000]
+    SEC_IMAGE: Literal[0x1000000]
+    SEC_LARGE_PAGES: Literal[0x80000000]
+    SEC_NOCACHE: Literal[0x10000000]
+    SEC_RESERVE: Literal[0x4000000]
+    SEC_WRITECOMBINE: Literal[0x40000000]
+
+    STARTF_USESHOWWINDOW: Literal[0x1]
+    STARTF_USESTDHANDLES: Literal[0x100]
+
+    STD_ERROR_HANDLE: Literal[0xFFFFFFF4]
+    STD_OUTPUT_HANDLE: Literal[0xFFFFFFF5]
+    STD_INPUT_HANDLE: Literal[0xFFFFFFF6]
+
+    STILL_ACTIVE: Literal[259]
+    SW_HIDE: Literal[0]
+    SYNCHRONIZE: Literal[0x100000]
+    WAIT_ABANDONED_0: Literal[128]
+    WAIT_OBJECT_0: Literal[0]
+    WAIT_TIMEOUT: Literal[258]
+
+    if sys.version_info >= (3, 10):
+        LOCALE_NAME_INVARIANT: str
+        LOCALE_NAME_MAX_LENGTH: int
+        LOCALE_NAME_SYSTEM_DEFAULT: str
+        LOCALE_NAME_USER_DEFAULT: str | None
+
+        LCMAP_FULLWIDTH: int
+        LCMAP_HALFWIDTH: int
+        LCMAP_HIRAGANA: int
+        LCMAP_KATAKANA: int
+        LCMAP_LINGUISTIC_CASING: int
+        LCMAP_LOWERCASE: int
+        LCMAP_SIMPLIFIED_CHINESE: int
+        LCMAP_TITLECASE: int
+        LCMAP_TRADITIONAL_CHINESE: int
+        LCMAP_UPPERCASE: int
+
+    if sys.version_info >= (3, 12):
+        COPYFILE2_CALLBACK_CHUNK_STARTED: Literal[1]
+        COPYFILE2_CALLBACK_CHUNK_FINISHED: Literal[2]
+        COPYFILE2_CALLBACK_STREAM_STARTED: Literal[3]
+        COPYFILE2_CALLBACK_STREAM_FINISHED: Literal[4]
+        COPYFILE2_CALLBACK_POLL_CONTINUE: Literal[5]
+        COPYFILE2_CALLBACK_ERROR: Literal[6]
+
+        COPYFILE2_PROGRESS_CONTINUE: Literal[0]
+        COPYFILE2_PROGRESS_CANCEL: Literal[1]
+        COPYFILE2_PROGRESS_STOP: Literal[2]
+        COPYFILE2_PROGRESS_QUIET: Literal[3]
+        COPYFILE2_PROGRESS_PAUSE: Literal[4]
+
+        COPY_FILE_FAIL_IF_EXISTS: Literal[0x1]
+        COPY_FILE_RESTARTABLE: Literal[0x2]
+        COPY_FILE_OPEN_SOURCE_FOR_WRITE: Literal[0x4]
+        COPY_FILE_ALLOW_DECRYPTED_DESTINATION: Literal[0x8]
+        COPY_FILE_COPY_SYMLINK: Literal[0x800]
+        COPY_FILE_NO_BUFFERING: Literal[0x1000]
+        COPY_FILE_REQUEST_SECURITY_PRIVILEGES: Literal[0x2000]
+        COPY_FILE_RESUME_FROM_PAUSE: Literal[0x4000]
+        COPY_FILE_NO_OFFLOAD: Literal[0x40000]
+        COPY_FILE_REQUEST_COMPRESSED_TRAFFIC: Literal[0x10000000]
+
+        ERROR_ACCESS_DENIED: Literal[5]
+        ERROR_PRIVILEGE_NOT_HELD: Literal[1314]
+
+    def CloseHandle(handle: int, /) -> None: ...
+    @overload
+    def ConnectNamedPipe(handle: int, overlapped: Literal[True]) -> Overlapped: ...
+    @overload
+    def ConnectNamedPipe(handle: int, overlapped: Literal[False] = False) -> None: ...
+    @overload
+    def ConnectNamedPipe(handle: int, overlapped: bool) -> Overlapped | None: ...
+    def CreateFile(
+        file_name: str,
+        desired_access: int,
+        share_mode: int,
+        security_attributes: int,
+        creation_disposition: int,
+        flags_and_attributes: int,
+        template_file: int,
+        /,
+    ) -> int: ...
+    def CreateJunction(src_path: str, dst_path: str, /) -> None: ...
+    def CreateNamedPipe(
+        name: str,
+        open_mode: int,
+        pipe_mode: int,
+        max_instances: int,
+        out_buffer_size: int,
+        in_buffer_size: int,
+        default_timeout: int,
+        security_attributes: int,
+        /,
+    ) -> int: ...
+    def CreatePipe(pipe_attrs: Any, size: int, /) -> tuple[int, int]: ...
+    def CreateProcess(
+        application_name: str | None,
+        command_line: str | None,
+        proc_attrs: Any,
+        thread_attrs: Any,
+        inherit_handles: bool,
+        creation_flags: int,
+        env_mapping: dict[str, str],
+        current_directory: str | None,
+        startup_info: Any,
+        /,
+    ) -> tuple[int, int, int, int]: ...
+    def DuplicateHandle(
+        source_process_handle: int,
+        source_handle: int,
+        target_process_handle: int,
+        desired_access: int,
+        inherit_handle: bool,
+        options: int = 0,
+        /,
+    ) -> int: ...
+    def ExitProcess(ExitCode: int, /) -> NoReturn: ...
+    def GetACP() -> int: ...
+    def GetFileType(handle: int) -> int: ...
+    def GetCurrentProcess() -> int: ...
+    def GetExitCodeProcess(process: int, /) -> int: ...
+    def GetLastError() -> int: ...
+    def GetModuleFileName(module_handle: int, /) -> str: ...
+    def GetStdHandle(std_handle: int, /) -> int: ...
+    def GetVersion() -> int: ...
+    def OpenProcess(desired_access: int, inherit_handle: bool, process_id: int, /) -> int: ...
+    def PeekNamedPipe(handle: int, size: int = 0, /) -> tuple[int, int] | tuple[bytes, int, int]: ...
+    if sys.version_info >= (3, 10):
+        def LCMapStringEx(locale: str, flags: int, src: str) -> str: ...
+        def UnmapViewOfFile(address: int, /) -> None: ...
+
+    @overload
+    def ReadFile(handle: int, size: int, overlapped: Literal[True]) -> tuple[Overlapped, int]: ...
+    @overload
+    def ReadFile(handle: int, size: int, overlapped: Literal[False] = False) -> tuple[bytes, int]: ...
+    @overload
+    def ReadFile(handle: int, size: int, overlapped: int | bool) -> tuple[Any, int]: ...
+    def SetNamedPipeHandleState(
+        named_pipe: int, mode: int | None, max_collection_count: int | None, collect_data_timeout: int | None, /
+    ) -> None: ...
+    def TerminateProcess(handle: int, exit_code: int, /) -> None: ...
+    def WaitForMultipleObjects(handle_seq: Sequence[int], wait_flag: bool, milliseconds: int = 0xFFFFFFFF, /) -> int: ...
+    def WaitForSingleObject(handle: int, milliseconds: int, /) -> int: ...
+    def WaitNamedPipe(name: str, timeout: int, /) -> None: ...
+    @overload
+    def WriteFile(handle: int, buffer: ReadableBuffer, overlapped: Literal[True]) -> tuple[Overlapped, int]: ...
+    @overload
+    def WriteFile(handle: int, buffer: ReadableBuffer, overlapped: Literal[False] = False) -> tuple[int, int]: ...
+    @overload
+    def WriteFile(handle: int, buffer: ReadableBuffer, overlapped: int | bool) -> tuple[Any, int]: ...
+    @final
+    class Overlapped:
+        event: int
+        def GetOverlappedResult(self, wait: bool, /) -> tuple[int, int]: ...
+        def cancel(self) -> None: ...
+        def getbuffer(self) -> bytes | None: ...
+
+    if sys.version_info >= (3, 12):
+        def CopyFile2(existing_file_name: str, new_file_name: str, flags: int, progress_routine: int | None = None) -> int: ...
+        def NeedCurrentDirectoryForExePath(exe_name: str, /) -> bool: ...

crates/red_knot/vendor/typeshed/stdlib/abc.pyi

@@ -0,0 +1,51 @@
+import _typeshed
+import sys
+from _typeshed import SupportsWrite
+from collections.abc import Callable
+from typing import Any, Literal, TypeVar
+from typing_extensions import Concatenate, ParamSpec, deprecated
+
+_T = TypeVar("_T")
+_R_co = TypeVar("_R_co", covariant=True)
+_FuncT = TypeVar("_FuncT", bound=Callable[..., Any])
+_P = ParamSpec("_P")
+
+# These definitions have special processing in mypy
+class ABCMeta(type):
+    __abstractmethods__: frozenset[str]
+    if sys.version_info >= (3, 11):
+        def __new__(
+            mcls: type[_typeshed.Self], name: str, bases: tuple[type, ...], namespace: dict[str, Any], /, **kwargs: Any
+        ) -> _typeshed.Self: ...
+    else:
+        def __new__(
+            mcls: type[_typeshed.Self], name: str, bases: tuple[type, ...], namespace: dict[str, Any], **kwargs: Any
+        ) -> _typeshed.Self: ...
+
+    def __instancecheck__(cls: ABCMeta, instance: Any) -> bool: ...
+    def __subclasscheck__(cls: ABCMeta, subclass: type) -> bool: ...
+    def _dump_registry(cls: ABCMeta, file: SupportsWrite[str] | None = None) -> None: ...
+    def register(cls: ABCMeta, subclass: type[_T]) -> type[_T]: ...
+
+def abstractmethod(funcobj: _FuncT) -> _FuncT: ...
+@deprecated("Deprecated, use 'classmethod' with 'abstractmethod' instead")
+class abstractclassmethod(classmethod[_T, _P, _R_co]):
+    __isabstractmethod__: Literal[True]
+    def __init__(self, callable: Callable[Concatenate[type[_T], _P], _R_co]) -> None: ...
+
+@deprecated("Deprecated, use 'staticmethod' with 'abstractmethod' instead")
+class abstractstaticmethod(staticmethod[_P, _R_co]):
+    __isabstractmethod__: Literal[True]
+    def __init__(self, callable: Callable[_P, _R_co]) -> None: ...
+
+@deprecated("Deprecated, use 'property' with 'abstractmethod' instead")
+class abstractproperty(property):
+    __isabstractmethod__: Literal[True]
+
+class ABC(metaclass=ABCMeta):
+    __slots__ = ()
+
+def get_cache_token() -> object: ...
+
+if sys.version_info >= (3, 10):
+    def update_abstractmethods(cls: type[_T]) -> type[_T]: ...

crates/red_knot/vendor/typeshed/stdlib/aifc.pyi

@@ -0,0 +1,91 @@
+import sys
+from types import TracebackType
+from typing import IO, Any, Literal, NamedTuple, overload
+from typing_extensions import Self, TypeAlias
+
+if sys.version_info >= (3, 9):
+    __all__ = ["Error", "open"]
+else:
+    __all__ = ["Error", "open", "openfp"]
+
+class Error(Exception): ...
+
+class _aifc_params(NamedTuple):
+    nchannels: int
+    sampwidth: int
+    framerate: int
+    nframes: int
+    comptype: bytes
+    compname: bytes
+
+_File: TypeAlias = str | IO[bytes]
+_Marker: TypeAlias = tuple[int, int, bytes]
+
+class Aifc_read:
+    def __init__(self, f: _File) -> None: ...
+    def __enter__(self) -> Self: ...
+    def __exit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
+    ) -> None: ...
+    def initfp(self, file: IO[bytes]) -> None: ...
+    def getfp(self) -> IO[bytes]: ...
+    def rewind(self) -> None: ...
+    def close(self) -> None: ...
+    def tell(self) -> int: ...
+    def getnchannels(self) -> int: ...
+    def getnframes(self) -> int: ...
+    def getsampwidth(self) -> int: ...
+    def getframerate(self) -> int: ...
+    def getcomptype(self) -> bytes: ...
+    def getcompname(self) -> bytes: ...
+    def getparams(self) -> _aifc_params: ...
+    def getmarkers(self) -> list[_Marker] | None: ...
+    def getmark(self, id: int) -> _Marker: ...
+    def setpos(self, pos: int) -> None: ...
+    def readframes(self, nframes: int) -> bytes: ...
+
+class Aifc_write:
+    def __init__(self, f: _File) -> None: ...
+    def __del__(self) -> None: ...
+    def __enter__(self) -> Self: ...
+    def __exit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
+    ) -> None: ...
+    def initfp(self, file: IO[bytes]) -> None: ...
+    def aiff(self) -> None: ...
+    def aifc(self) -> None: ...
+    def setnchannels(self, nchannels: int) -> None: ...
+    def getnchannels(self) -> int: ...
+    def setsampwidth(self, sampwidth: int) -> None: ...
+    def getsampwidth(self) -> int: ...
+    def setframerate(self, framerate: int) -> None: ...
+    def getframerate(self) -> int: ...
+    def setnframes(self, nframes: int) -> None: ...
+    def getnframes(self) -> int: ...
+    def setcomptype(self, comptype: bytes, compname: bytes) -> None: ...
+    def getcomptype(self) -> bytes: ...
+    def getcompname(self) -> bytes: ...
+    def setparams(self, params: tuple[int, int, int, int, bytes, bytes]) -> None: ...
+    def getparams(self) -> _aifc_params: ...
+    def setmark(self, id: int, pos: int, name: bytes) -> None: ...
+    def getmark(self, id: int) -> _Marker: ...
+    def getmarkers(self) -> list[_Marker] | None: ...
+    def tell(self) -> int: ...
+    def writeframesraw(self, data: Any) -> None: ...  # Actual type for data is Buffer Protocol
+    def writeframes(self, data: Any) -> None: ...
+    def close(self) -> None: ...
+
+@overload
+def open(f: _File, mode: Literal["r", "rb"]) -> Aifc_read: ...
+@overload
+def open(f: _File, mode: Literal["w", "wb"]) -> Aifc_write: ...
+@overload
+def open(f: _File, mode: str | None = None) -> Any: ...
+
+if sys.version_info < (3, 9):
+    @overload
+    def openfp(f: _File, mode: Literal["r", "rb"]) -> Aifc_read: ...
+    @overload
+    def openfp(f: _File, mode: Literal["w", "wb"]) -> Aifc_write: ...
+    @overload
+    def openfp(f: _File, mode: str | None = None) -> Any: ...

crates/red_knot/vendor/typeshed/stdlib/antigravity.pyi

@@ -0,0 +1,3 @@
+from _typeshed import ReadableBuffer
+
+def geohash(latitude: float, longitude: float, datedow: ReadableBuffer) -> None: ...

crates/red_knot/vendor/typeshed/stdlib/argparse.pyi

@@ -0,0 +1,753 @@
+import sys
+from _typeshed import sentinel
+from collections.abc import Callable, Generator, Iterable, Sequence
+from re import Pattern
+from typing import IO, Any, Generic, Literal, NewType, NoReturn, Protocol, TypeVar, overload
+from typing_extensions import Self, TypeAlias, deprecated
+
+__all__ = [
+    "ArgumentParser",
+    "ArgumentError",
+    "ArgumentTypeError",
+    "FileType",
+    "HelpFormatter",
+    "ArgumentDefaultsHelpFormatter",
+    "RawDescriptionHelpFormatter",
+    "RawTextHelpFormatter",
+    "MetavarTypeHelpFormatter",
+    "Namespace",
+    "Action",
+    "ONE_OR_MORE",
+    "OPTIONAL",
+    "PARSER",
+    "REMAINDER",
+    "SUPPRESS",
+    "ZERO_OR_MORE",
+]
+
+if sys.version_info >= (3, 9):
+    __all__ += ["BooleanOptionalAction"]
+
+_T = TypeVar("_T")
+_ActionT = TypeVar("_ActionT", bound=Action)
+_ArgumentParserT = TypeVar("_ArgumentParserT", bound=ArgumentParser)
+_N = TypeVar("_N")
+# more precisely, Literal["store", "store_const", "store_true",
+# "store_false", "append", "append_const", "count", "help", "version",
+# "extend"], but using this would make it hard to annotate callers
+# that don't use a literal argument
+_ActionStr: TypeAlias = str
+# more precisely, Literal["?", "*", "+", "...", "A...",
+# "==SUPPRESS=="], but using this would make it hard to annotate
+# callers that don't use a literal argument
+_NArgsStr: TypeAlias = str
+
+ONE_OR_MORE: Literal["+"]
+OPTIONAL: Literal["?"]
+PARSER: Literal["A..."]
+REMAINDER: Literal["..."]
+_SUPPRESS_T = NewType("_SUPPRESS_T", str)
+SUPPRESS: _SUPPRESS_T | str  # not using Literal because argparse sometimes compares SUPPRESS with is
+# the | str is there so that foo = argparse.SUPPRESS; foo = "test" checks out in mypy
+ZERO_OR_MORE: Literal["*"]
+_UNRECOGNIZED_ARGS_ATTR: str  # undocumented
+
+class ArgumentError(Exception):
+    argument_name: str | None
+    message: str
+    def __init__(self, argument: Action | None, message: str) -> None: ...
+
+# undocumented
+class _AttributeHolder:
+    def _get_kwargs(self) -> list[tuple[str, Any]]: ...
+    def _get_args(self) -> list[Any]: ...
+
+# undocumented
+class _ActionsContainer:
+    description: str | None
+    prefix_chars: str
+    argument_default: Any
+    conflict_handler: str
+
+    _registries: dict[str, dict[Any, Any]]
+    _actions: list[Action]
+    _option_string_actions: dict[str, Action]
+    _action_groups: list[_ArgumentGroup]
+    _mutually_exclusive_groups: list[_MutuallyExclusiveGroup]
+    _defaults: dict[str, Any]
+    _negative_number_matcher: Pattern[str]
+    _has_negative_number_optionals: list[bool]
+    def __init__(self, description: str | None, prefix_chars: str, argument_default: Any, conflict_handler: str) -> None: ...
+    def register(self, registry_name: str, value: Any, object: Any) -> None: ...
+    def _registry_get(self, registry_name: str, value: Any, default: Any = None) -> Any: ...
+    def set_defaults(self, **kwargs: Any) -> None: ...
+    def get_default(self, dest: str) -> Any: ...
+    def add_argument(
+        self,
+        *name_or_flags: str,
+        action: _ActionStr | type[Action] = ...,
+        nargs: int | _NArgsStr | _SUPPRESS_T | None = None,
+        const: Any = ...,
+        default: Any = ...,
+        type: Callable[[str], _T] | FileType = ...,
+        choices: Iterable[_T] | None = ...,
+        required: bool = ...,
+        help: str | None = ...,
+        metavar: str | tuple[str, ...] | None = ...,
+        dest: str | None = ...,
+        version: str = ...,
+        **kwargs: Any,
+    ) -> Action: ...
+    def add_argument_group(
+        self,
+        title: str | None = None,
+        description: str | None = None,
+        *,
+        prefix_chars: str = ...,
+        argument_default: Any = ...,
+        conflict_handler: str = ...,
+    ) -> _ArgumentGroup: ...
+    def add_mutually_exclusive_group(self, *, required: bool = False) -> _MutuallyExclusiveGroup: ...
+    def _add_action(self, action: _ActionT) -> _ActionT: ...
+    def _remove_action(self, action: Action) -> None: ...
+    def _add_container_actions(self, container: _ActionsContainer) -> None: ...
+    def _get_positional_kwargs(self, dest: str, **kwargs: Any) -> dict[str, Any]: ...
+    def _get_optional_kwargs(self, *args: Any, **kwargs: Any) -> dict[str, Any]: ...
+    def _pop_action_class(self, kwargs: Any, default: type[Action] | None = None) -> type[Action]: ...
+    def _get_handler(self) -> Callable[[Action, Iterable[tuple[str, Action]]], Any]: ...
+    def _check_conflict(self, action: Action) -> None: ...
+    def _handle_conflict_error(self, action: Action, conflicting_actions: Iterable[tuple[str, Action]]) -> NoReturn: ...
+    def _handle_conflict_resolve(self, action: Action, conflicting_actions: Iterable[tuple[str, Action]]) -> None: ...
+
+class _FormatterClass(Protocol):
+    def __call__(self, *, prog: str) -> HelpFormatter: ...
+
+class ArgumentParser(_AttributeHolder, _ActionsContainer):
+    prog: str
+    usage: str | None
+    epilog: str | None
+    formatter_class: _FormatterClass
+    fromfile_prefix_chars: str | None
+    add_help: bool
+    allow_abbrev: bool
+
+    # undocumented
+    _positionals: _ArgumentGroup
+    _optionals: _ArgumentGroup
+    _subparsers: _ArgumentGroup | None
+
+    # Note: the constructor arguments are also used in _SubParsersAction.add_parser.
+    if sys.version_info >= (3, 9):
+        def __init__(
+            self,
+            prog: str | None = None,
+            usage: str | None = None,
+            description: str | None = None,
+            epilog: str | None = None,
+            parents: Sequence[ArgumentParser] = [],
+            formatter_class: _FormatterClass = ...,
+            prefix_chars: str = "-",
+            fromfile_prefix_chars: str | None = None,
+            argument_default: Any = None,
+            conflict_handler: str = "error",
+            add_help: bool = True,
+            allow_abbrev: bool = True,
+            exit_on_error: bool = True,
+        ) -> None: ...
+    else:
+        def __init__(
+            self,
+            prog: str | None = None,
+            usage: str | None = None,
+            description: str | None = None,
+            epilog: str | None = None,
+            parents: Sequence[ArgumentParser] = [],
+            formatter_class: _FormatterClass = ...,
+            prefix_chars: str = "-",
+            fromfile_prefix_chars: str | None = None,
+            argument_default: Any = None,
+            conflict_handler: str = "error",
+            add_help: bool = True,
+            allow_abbrev: bool = True,
+        ) -> None: ...
+
+    @overload
+    def parse_args(self, args: Sequence[str] | None = None, namespace: None = None) -> Namespace: ...
+    @overload
+    def parse_args(self, args: Sequence[str] | None, namespace: _N) -> _N: ...
+    @overload
+    def parse_args(self, *, namespace: _N) -> _N: ...
+    @overload
+    def add_subparsers(
+        self: _ArgumentParserT,
+        *,
+        title: str = ...,
+        description: str | None = ...,
+        prog: str = ...,
+        action: type[Action] = ...,
+        option_string: str = ...,
+        dest: str | None = ...,
+        required: bool = ...,
+        help: str | None = ...,
+        metavar: str | None = ...,
+    ) -> _SubParsersAction[_ArgumentParserT]: ...
+    @overload
+    def add_subparsers(
+        self,
+        *,
+        title: str = ...,
+        description: str | None = ...,
+        prog: str = ...,
+        parser_class: type[_ArgumentParserT],
+        action: type[Action] = ...,
+        option_string: str = ...,
+        dest: str | None = ...,
+        required: bool = ...,
+        help: str | None = ...,
+        metavar: str | None = ...,
+    ) -> _SubParsersAction[_ArgumentParserT]: ...
+    def print_usage(self, file: IO[str] | None = None) -> None: ...
+    def print_help(self, file: IO[str] | None = None) -> None: ...
+    def format_usage(self) -> str: ...
+    def format_help(self) -> str: ...
+    @overload
+    def parse_known_args(self, args: Sequence[str] | None = None, namespace: None = None) -> tuple[Namespace, list[str]]: ...
+    @overload
+    def parse_known_args(self, args: Sequence[str] | None, namespace: _N) -> tuple[_N, list[str]]: ...
+    @overload
+    def parse_known_args(self, *, namespace: _N) -> tuple[_N, list[str]]: ...
+    def convert_arg_line_to_args(self, arg_line: str) -> list[str]: ...
+    def exit(self, status: int = 0, message: str | None = None) -> NoReturn: ...
+    def error(self, message: str) -> NoReturn: ...
+    @overload
+    def parse_intermixed_args(self, args: Sequence[str] | None = None, namespace: None = None) -> Namespace: ...
+    @overload
+    def parse_intermixed_args(self, args: Sequence[str] | None, namespace: _N) -> _N: ...
+    @overload
+    def parse_intermixed_args(self, *, namespace: _N) -> _N: ...
+    @overload
+    def parse_known_intermixed_args(
+        self, args: Sequence[str] | None = None, namespace: None = None
+    ) -> tuple[Namespace, list[str]]: ...
+    @overload
+    def parse_known_intermixed_args(self, args: Sequence[str] | None, namespace: _N) -> tuple[_N, list[str]]: ...
+    @overload
+    def parse_known_intermixed_args(self, *, namespace: _N) -> tuple[_N, list[str]]: ...
+    # undocumented
+    def _get_optional_actions(self) -> list[Action]: ...
+    def _get_positional_actions(self) -> list[Action]: ...
+    def _parse_known_args(self, arg_strings: list[str], namespace: Namespace) -> tuple[Namespace, list[str]]: ...
+    def _read_args_from_files(self, arg_strings: list[str]) -> list[str]: ...
+    def _match_argument(self, action: Action, arg_strings_pattern: str) -> int: ...
+    def _match_arguments_partial(self, actions: Sequence[Action], arg_strings_pattern: str) -> list[int]: ...
+    def _parse_optional(self, arg_string: str) -> tuple[Action | None, str, str | None] | None: ...
+    def _get_option_tuples(self, option_string: str) -> list[tuple[Action, str, str | None]]: ...
+    def _get_nargs_pattern(self, action: Action) -> str: ...
+    def _get_values(self, action: Action, arg_strings: list[str]) -> Any: ...
+    def _get_value(self, action: Action, arg_string: str) -> Any: ...
+    def _check_value(self, action: Action, value: Any) -> None: ...
+    def _get_formatter(self) -> HelpFormatter: ...
+    def _print_message(self, message: str, file: IO[str] | None = None) -> None: ...
+
+class HelpFormatter:
+    # undocumented
+    _prog: str
+    _indent_increment: int
+    _max_help_position: int
+    _width: int
+    _current_indent: int
+    _level: int
+    _action_max_length: int
+    _root_section: _Section
+    _current_section: _Section
+    _whitespace_matcher: Pattern[str]
+    _long_break_matcher: Pattern[str]
+
+    class _Section:
+        formatter: HelpFormatter
+        heading: str | None
+        parent: Self | None
+        items: list[tuple[Callable[..., str], Iterable[Any]]]
+        def __init__(self, formatter: HelpFormatter, parent: Self | None, heading: str | None = None) -> None: ...
+        def format_help(self) -> str: ...
+
+    def __init__(self, prog: str, indent_increment: int = 2, max_help_position: int = 24, width: int | None = None) -> None: ...
+    def _indent(self) -> None: ...
+    def _dedent(self) -> None: ...
+    def _add_item(self, func: Callable[..., str], args: Iterable[Any]) -> None: ...
+    def start_section(self, heading: str | None) -> None: ...
+    def end_section(self) -> None: ...
+    def add_text(self, text: str | None) -> None: ...
+    def add_usage(
+        self, usage: str | None, actions: Iterable[Action], groups: Iterable[_MutuallyExclusiveGroup], prefix: str | None = None
+    ) -> None: ...
+    def add_argument(self, action: Action) -> None: ...
+    def add_arguments(self, actions: Iterable[Action]) -> None: ...
+    def format_help(self) -> str: ...
+    def _join_parts(self, part_strings: Iterable[str]) -> str: ...
+    def _format_usage(
+        self, usage: str | None, actions: Iterable[Action], groups: Iterable[_MutuallyExclusiveGroup], prefix: str | None
+    ) -> str: ...
+    def _format_actions_usage(self, actions: Iterable[Action], groups: Iterable[_MutuallyExclusiveGroup]) -> str: ...
+    def _format_text(self, text: str) -> str: ...
+    def _format_action(self, action: Action) -> str: ...
+    def _format_action_invocation(self, action: Action) -> str: ...
+    def _metavar_formatter(self, action: Action, default_metavar: str) -> Callable[[int], tuple[str, ...]]: ...
+    def _format_args(self, action: Action, default_metavar: str) -> str: ...
+    def _expand_help(self, action: Action) -> str: ...
+    def _iter_indented_subactions(self, action: Action) -> Generator[Action, None, None]: ...
+    def _split_lines(self, text: str, width: int) -> list[str]: ...
+    def _fill_text(self, text: str, width: int, indent: str) -> str: ...
+    def _get_help_string(self, action: Action) -> str | None: ...
+    def _get_default_metavar_for_optional(self, action: Action) -> str: ...
+    def _get_default_metavar_for_positional(self, action: Action) -> str: ...
+
+class RawDescriptionHelpFormatter(HelpFormatter): ...
+class RawTextHelpFormatter(RawDescriptionHelpFormatter): ...
+class ArgumentDefaultsHelpFormatter(HelpFormatter): ...
+class MetavarTypeHelpFormatter(HelpFormatter): ...
+
+class Action(_AttributeHolder):
+    option_strings: Sequence[str]
+    dest: str
+    nargs: int | str | None
+    const: Any
+    default: Any
+    type: Callable[[str], Any] | FileType | None
+    choices: Iterable[Any] | None
+    required: bool
+    help: str | None
+    metavar: str | tuple[str, ...] | None
+    if sys.version_info >= (3, 13):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            nargs: int | str | None = None,
+            const: _T | None = None,
+            default: _T | str | None = None,
+            type: Callable[[str], _T] | FileType | None = None,
+            choices: Iterable[_T] | None = None,
+            required: bool = False,
+            help: str | None = None,
+            metavar: str | tuple[str, ...] | None = None,
+            deprecated: bool = False,
+        ) -> None: ...
+    else:
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            nargs: int | str | None = None,
+            const: _T | None = None,
+            default: _T | str | None = None,
+            type: Callable[[str], _T] | FileType | None = None,
+            choices: Iterable[_T] | None = None,
+            required: bool = False,
+            help: str | None = None,
+            metavar: str | tuple[str, ...] | None = None,
+        ) -> None: ...
+
+    def __call__(
+        self, parser: ArgumentParser, namespace: Namespace, values: str | Sequence[Any] | None, option_string: str | None = None
+    ) -> None: ...
+    if sys.version_info >= (3, 9):
+        def format_usage(self) -> str: ...
+
+if sys.version_info >= (3, 12):
+    class BooleanOptionalAction(Action):
+        if sys.version_info >= (3, 13):
+            @overload
+            def __init__(
+                self,
+                option_strings: Sequence[str],
+                dest: str,
+                default: bool | None = None,
+                *,
+                required: bool = False,
+                help: str | None = None,
+                deprecated: bool = False,
+            ) -> None: ...
+            @overload
+            @deprecated("The `type`, `choices`, and `metavar` parameters are ignored and will be removed in Python 3.14.")
+            def __init__(
+                self,
+                option_strings: Sequence[str],
+                dest: str,
+                default: _T | bool | None = None,
+                type: Callable[[str], _T] | FileType | None = sentinel,
+                choices: Iterable[_T] | None = sentinel,
+                required: bool = False,
+                help: str | None = None,
+                metavar: str | tuple[str, ...] | None = sentinel,
+                deprecated: bool = False,
+            ) -> None: ...
+        else:
+            @overload
+            def __init__(
+                self,
+                option_strings: Sequence[str],
+                dest: str,
+                default: bool | None = None,
+                *,
+                required: bool = False,
+                help: str | None = None,
+            ) -> None: ...
+            @overload
+            @deprecated("The `type`, `choices`, and `metavar` parameters are ignored and will be removed in Python 3.14.")
+            def __init__(
+                self,
+                option_strings: Sequence[str],
+                dest: str,
+                default: _T | bool | None = None,
+                type: Callable[[str], _T] | FileType | None = sentinel,
+                choices: Iterable[_T] | None = sentinel,
+                required: bool = False,
+                help: str | None = None,
+                metavar: str | tuple[str, ...] | None = sentinel,
+            ) -> None: ...
+
+elif sys.version_info >= (3, 9):
+    class BooleanOptionalAction(Action):
+        @overload
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            default: bool | None = None,
+            *,
+            required: bool = False,
+            help: str | None = None,
+        ) -> None: ...
+        @overload
+        @deprecated("The `type`, `choices`, and `metavar` parameters are ignored and will be removed in Python 3.14.")
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            default: _T | bool | None = None,
+            type: Callable[[str], _T] | FileType | None = None,
+            choices: Iterable[_T] | None = None,
+            required: bool = False,
+            help: str | None = None,
+            metavar: str | tuple[str, ...] | None = None,
+        ) -> None: ...
+
+class Namespace(_AttributeHolder):
+    def __init__(self, **kwargs: Any) -> None: ...
+    def __getattr__(self, name: str) -> Any: ...
+    def __setattr__(self, name: str, value: Any, /) -> None: ...
+    def __contains__(self, key: str) -> bool: ...
+    def __eq__(self, other: object) -> bool: ...
+
+class FileType:
+    # undocumented
+    _mode: str
+    _bufsize: int
+    _encoding: str | None
+    _errors: str | None
+    def __init__(self, mode: str = "r", bufsize: int = -1, encoding: str | None = None, errors: str | None = None) -> None: ...
+    def __call__(self, string: str) -> IO[Any]: ...
+
+# undocumented
+class _ArgumentGroup(_ActionsContainer):
+    title: str | None
+    _group_actions: list[Action]
+    def __init__(
+        self,
+        container: _ActionsContainer,
+        title: str | None = None,
+        description: str | None = None,
+        *,
+        prefix_chars: str = ...,
+        argument_default: Any = ...,
+        conflict_handler: str = ...,
+    ) -> None: ...
+
+# undocumented
+class _MutuallyExclusiveGroup(_ArgumentGroup):
+    required: bool
+    _container: _ActionsContainer
+    def __init__(self, container: _ActionsContainer, required: bool = False) -> None: ...
+
+# undocumented
+class _StoreAction(Action): ...
+
+# undocumented
+class _StoreConstAction(Action):
+    if sys.version_info >= (3, 13):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            const: Any | None = None,
+            default: Any = None,
+            required: bool = False,
+            help: str | None = None,
+            metavar: str | tuple[str, ...] | None = None,
+            deprecated: bool = False,
+        ) -> None: ...
+    elif sys.version_info >= (3, 11):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            const: Any | None = None,
+            default: Any = None,
+            required: bool = False,
+            help: str | None = None,
+            metavar: str | tuple[str, ...] | None = None,
+        ) -> None: ...
+    else:
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            const: Any,
+            default: Any = None,
+            required: bool = False,
+            help: str | None = None,
+            metavar: str | tuple[str, ...] | None = None,
+        ) -> None: ...
+
+# undocumented
+class _StoreTrueAction(_StoreConstAction):
+    if sys.version_info >= (3, 13):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            default: bool = False,
+            required: bool = False,
+            help: str | None = None,
+            deprecated: bool = False,
+        ) -> None: ...
+    else:
+        def __init__(
+            self, option_strings: Sequence[str], dest: str, default: bool = False, required: bool = False, help: str | None = None
+        ) -> None: ...
+
+# undocumented
+class _StoreFalseAction(_StoreConstAction):
+    if sys.version_info >= (3, 13):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            default: bool = True,
+            required: bool = False,
+            help: str | None = None,
+            deprecated: bool = False,
+        ) -> None: ...
+    else:
+        def __init__(
+            self, option_strings: Sequence[str], dest: str, default: bool = True, required: bool = False, help: str | None = None
+        ) -> None: ...
+
+# undocumented
+class _AppendAction(Action): ...
+
+# undocumented
+class _ExtendAction(_AppendAction): ...
+
+# undocumented
+class _AppendConstAction(Action):
+    if sys.version_info >= (3, 13):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            const: Any | None = None,
+            default: Any = None,
+            required: bool = False,
+            help: str | None = None,
+            metavar: str | tuple[str, ...] | None = None,
+            deprecated: bool = False,
+        ) -> None: ...
+    elif sys.version_info >= (3, 11):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            const: Any | None = None,
+            default: Any = None,
+            required: bool = False,
+            help: str | None = None,
+            metavar: str | tuple[str, ...] | None = None,
+        ) -> None: ...
+    else:
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            const: Any,
+            default: Any = None,
+            required: bool = False,
+            help: str | None = None,
+            metavar: str | tuple[str, ...] | None = None,
+        ) -> None: ...
+
+# undocumented
+class _CountAction(Action):
+    if sys.version_info >= (3, 13):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str,
+            default: Any = None,
+            required: bool = False,
+            help: str | None = None,
+            deprecated: bool = False,
+        ) -> None: ...
+    else:
+        def __init__(
+            self, option_strings: Sequence[str], dest: str, default: Any = None, required: bool = False, help: str | None = None
+        ) -> None: ...
+
+# undocumented
+class _HelpAction(Action):
+    if sys.version_info >= (3, 13):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str = "==SUPPRESS==",
+            default: str = "==SUPPRESS==",
+            help: str | None = None,
+            deprecated: bool = False,
+        ) -> None: ...
+    else:
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            dest: str = "==SUPPRESS==",
+            default: str = "==SUPPRESS==",
+            help: str | None = None,
+        ) -> None: ...
+
+# undocumented
+class _VersionAction(Action):
+    version: str | None
+    if sys.version_info >= (3, 13):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            version: str | None = None,
+            dest: str = "==SUPPRESS==",
+            default: str = "==SUPPRESS==",
+            help: str | None = None,
+            deprecated: bool = False,
+        ) -> None: ...
+    elif sys.version_info >= (3, 11):
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            version: str | None = None,
+            dest: str = "==SUPPRESS==",
+            default: str = "==SUPPRESS==",
+            help: str | None = None,
+        ) -> None: ...
+    else:
+        def __init__(
+            self,
+            option_strings: Sequence[str],
+            version: str | None = None,
+            dest: str = "==SUPPRESS==",
+            default: str = "==SUPPRESS==",
+            help: str = "show program's version number and exit",
+        ) -> None: ...
+
+# undocumented
+class _SubParsersAction(Action, Generic[_ArgumentParserT]):
+    _ChoicesPseudoAction: type[Any]  # nested class
+    _prog_prefix: str
+    _parser_class: type[_ArgumentParserT]
+    _name_parser_map: dict[str, _ArgumentParserT]
+    choices: dict[str, _ArgumentParserT]
+    _choices_actions: list[Action]
+    def __init__(
+        self,
+        option_strings: Sequence[str],
+        prog: str,
+        parser_class: type[_ArgumentParserT],
+        dest: str = "==SUPPRESS==",
+        required: bool = False,
+        help: str | None = None,
+        metavar: str | tuple[str, ...] | None = None,
+    ) -> None: ...
+
+    # Note: `add_parser` accepts all kwargs of `ArgumentParser.__init__`. It also
+    # accepts its own `help` and `aliases` kwargs.
+    if sys.version_info >= (3, 13):
+        def add_parser(
+            self,
+            name: str,
+            *,
+            deprecated: bool = False,
+            help: str | None = ...,
+            aliases: Sequence[str] = ...,
+            # Kwargs from ArgumentParser constructor
+            prog: str | None = ...,
+            usage: str | None = ...,
+            description: str | None = ...,
+            epilog: str | None = ...,
+            parents: Sequence[_ArgumentParserT] = ...,
+            formatter_class: _FormatterClass = ...,
+            prefix_chars: str = ...,
+            fromfile_prefix_chars: str | None = ...,
+            argument_default: Any = ...,
+            conflict_handler: str = ...,
+            add_help: bool = ...,
+            allow_abbrev: bool = ...,
+            exit_on_error: bool = ...,
+        ) -> _ArgumentParserT: ...
+    elif sys.version_info >= (3, 9):
+        def add_parser(
+            self,
+            name: str,
+            *,
+            help: str | None = ...,
+            aliases: Sequence[str] = ...,
+            # Kwargs from ArgumentParser constructor
+            prog: str | None = ...,
+            usage: str | None = ...,
+            description: str | None = ...,
+            epilog: str | None = ...,
+            parents: Sequence[_ArgumentParserT] = ...,
+            formatter_class: _FormatterClass = ...,
+            prefix_chars: str = ...,
+            fromfile_prefix_chars: str | None = ...,
+            argument_default: Any = ...,
+            conflict_handler: str = ...,
+            add_help: bool = ...,
+            allow_abbrev: bool = ...,
+            exit_on_error: bool = ...,
+        ) -> _ArgumentParserT: ...
+    else:
+        def add_parser(
+            self,
+            name: str,
+            *,
+            help: str | None = ...,
+            aliases: Sequence[str] = ...,
+            # Kwargs from ArgumentParser constructor
+            prog: str | None = ...,
+            usage: str | None = ...,
+            description: str | None = ...,
+            epilog: str | None = ...,
+            parents: Sequence[_ArgumentParserT] = ...,
+            formatter_class: _FormatterClass = ...,
+            prefix_chars: str = ...,
+            fromfile_prefix_chars: str | None = ...,
+            argument_default: Any = ...,
+            conflict_handler: str = ...,
+            add_help: bool = ...,
+            allow_abbrev: bool = ...,
+        ) -> _ArgumentParserT: ...
+
+    def _get_subactions(self) -> list[Action]: ...
+
+# undocumented
+class ArgumentTypeError(Exception): ...
+
+# undocumented
+def _get_action_name(argument: Action | None) -> str | None: ...

crates/red_knot/vendor/typeshed/stdlib/array.pyi

@@ -0,0 +1,92 @@
+import sys
+from _typeshed import ReadableBuffer, SupportsRead, SupportsWrite
+from collections.abc import Iterable
+
+# pytype crashes if array inherits from collections.abc.MutableSequence instead of typing.MutableSequence
+from typing import Any, Literal, MutableSequence, SupportsIndex, TypeVar, overload  # noqa: Y022
+from typing_extensions import Self, TypeAlias
+
+if sys.version_info >= (3, 12):
+    from types import GenericAlias
+
+_IntTypeCode: TypeAlias = Literal["b", "B", "h", "H", "i", "I", "l", "L", "q", "Q"]
+_FloatTypeCode: TypeAlias = Literal["f", "d"]
+_UnicodeTypeCode: TypeAlias = Literal["u"]
+_TypeCode: TypeAlias = _IntTypeCode | _FloatTypeCode | _UnicodeTypeCode
+
+_T = TypeVar("_T", int, float, str)
+
+typecodes: str
+
+class array(MutableSequence[_T]):
+    @property
+    def typecode(self) -> _TypeCode: ...
+    @property
+    def itemsize(self) -> int: ...
+    @overload
+    def __init__(self: array[int], typecode: _IntTypeCode, initializer: bytes | bytearray | Iterable[int] = ..., /) -> None: ...
+    @overload
+    def __init__(
+        self: array[float], typecode: _FloatTypeCode, initializer: bytes | bytearray | Iterable[float] = ..., /
+    ) -> None: ...
+    @overload
+    def __init__(
+        self: array[str], typecode: _UnicodeTypeCode, initializer: bytes | bytearray | Iterable[str] = ..., /
+    ) -> None: ...
+    @overload
+    def __init__(self, typecode: str, initializer: Iterable[_T], /) -> None: ...
+    @overload
+    def __init__(self, typecode: str, initializer: bytes | bytearray = ..., /) -> None: ...
+    def append(self, v: _T, /) -> None: ...
+    def buffer_info(self) -> tuple[int, int]: ...
+    def byteswap(self) -> None: ...
+    def count(self, v: _T, /) -> int: ...
+    def extend(self, bb: Iterable[_T], /) -> None: ...
+    def frombytes(self, buffer: ReadableBuffer, /) -> None: ...
+    def fromfile(self, f: SupportsRead[bytes], n: int, /) -> None: ...
+    def fromlist(self, list: list[_T], /) -> None: ...
+    def fromunicode(self, ustr: str, /) -> None: ...
+    if sys.version_info >= (3, 10):
+        def index(self, v: _T, start: int = 0, stop: int = sys.maxsize, /) -> int: ...
+    else:
+        def index(self, v: _T, /) -> int: ...  # type: ignore[override]
+
+    def insert(self, i: int, v: _T, /) -> None: ...
+    def pop(self, i: int = -1, /) -> _T: ...
+    def remove(self, v: _T, /) -> None: ...
+    def tobytes(self) -> bytes: ...
+    def tofile(self, f: SupportsWrite[bytes], /) -> None: ...
+    def tolist(self) -> list[_T]: ...
+    def tounicode(self) -> str: ...
+    if sys.version_info < (3, 9):
+        def fromstring(self, buffer: str | ReadableBuffer, /) -> None: ...
+        def tostring(self) -> bytes: ...
+
+    def __len__(self) -> int: ...
+    @overload
+    def __getitem__(self, key: SupportsIndex, /) -> _T: ...
+    @overload
+    def __getitem__(self, key: slice, /) -> array[_T]: ...
+    @overload  # type: ignore[override]
+    def __setitem__(self, key: SupportsIndex, value: _T, /) -> None: ...
+    @overload
+    def __setitem__(self, key: slice, value: array[_T], /) -> None: ...
+    def __delitem__(self, key: SupportsIndex | slice, /) -> None: ...
+    def __add__(self, value: array[_T], /) -> array[_T]: ...
+    def __eq__(self, value: object, /) -> bool: ...
+    def __ge__(self, value: array[_T], /) -> bool: ...
+    def __gt__(self, value: array[_T], /) -> bool: ...
+    def __iadd__(self, value: array[_T], /) -> Self: ...  # type: ignore[override]
+    def __imul__(self, value: int, /) -> Self: ...
+    def __le__(self, value: array[_T], /) -> bool: ...
+    def __lt__(self, value: array[_T], /) -> bool: ...
+    def __mul__(self, value: int, /) -> array[_T]: ...
+    def __rmul__(self, value: int, /) -> array[_T]: ...
+    def __copy__(self) -> array[_T]: ...
+    def __deepcopy__(self, unused: Any, /) -> array[_T]: ...
+    def __buffer__(self, flags: int, /) -> memoryview: ...
+    def __release_buffer__(self, buffer: memoryview, /) -> None: ...
+    if sys.version_info >= (3, 12):
+        def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
+
+ArrayType = array

crates/red_knot/vendor/typeshed/stdlib/ast.pyi

@@ -0,0 +1,367 @@
+import os
+import sys
+from _ast import *
+from _typeshed import ReadableBuffer, Unused
+from collections.abc import Iterator
+from typing import Any, Literal, TypeVar as _TypeVar, overload
+from typing_extensions import deprecated
+
+class _ABC(type):
+    if sys.version_info >= (3, 9):
+        def __init__(cls, *args: Unused) -> None: ...
+
+@deprecated("Replaced by ast.Constant; removal scheduled for Python 3.14")
+class Num(Constant, metaclass=_ABC):
+    value: int | float | complex
+
+@deprecated("Replaced by ast.Constant; removal scheduled for Python 3.14")
+class Str(Constant, metaclass=_ABC):
+    value: str
+    # Aliases for value, for backwards compatibility
+    s: str
+
+@deprecated("Replaced by ast.Constant; removal scheduled for Python 3.14")
+class Bytes(Constant, metaclass=_ABC):
+    value: bytes
+    # Aliases for value, for backwards compatibility
+    s: bytes
+
+@deprecated("Replaced by ast.Constant; removal scheduled for Python 3.14")
+class NameConstant(Constant, metaclass=_ABC): ...
+
+@deprecated("Replaced by ast.Constant; removal scheduled for Python 3.14")
+class Ellipsis(Constant, metaclass=_ABC): ...
+
+if sys.version_info >= (3, 9):
+    class slice(AST): ...
+    class ExtSlice(slice): ...
+    class Index(slice): ...
+    class Suite(mod): ...
+    class AugLoad(expr_context): ...
+    class AugStore(expr_context): ...
+    class Param(expr_context): ...
+
+class NodeVisitor:
+    def visit(self, node: AST) -> Any: ...
+    def generic_visit(self, node: AST) -> Any: ...
+    def visit_Module(self, node: Module) -> Any: ...
+    def visit_Interactive(self, node: Interactive) -> Any: ...
+    def visit_Expression(self, node: Expression) -> Any: ...
+    def visit_FunctionDef(self, node: FunctionDef) -> Any: ...
+    def visit_AsyncFunctionDef(self, node: AsyncFunctionDef) -> Any: ...
+    def visit_ClassDef(self, node: ClassDef) -> Any: ...
+    def visit_Return(self, node: Return) -> Any: ...
+    def visit_Delete(self, node: Delete) -> Any: ...
+    def visit_Assign(self, node: Assign) -> Any: ...
+    def visit_AugAssign(self, node: AugAssign) -> Any: ...
+    def visit_AnnAssign(self, node: AnnAssign) -> Any: ...
+    def visit_For(self, node: For) -> Any: ...
+    def visit_AsyncFor(self, node: AsyncFor) -> Any: ...
+    def visit_While(self, node: While) -> Any: ...
+    def visit_If(self, node: If) -> Any: ...
+    def visit_With(self, node: With) -> Any: ...
+    def visit_AsyncWith(self, node: AsyncWith) -> Any: ...
+    def visit_Raise(self, node: Raise) -> Any: ...
+    def visit_Try(self, node: Try) -> Any: ...
+    def visit_Assert(self, node: Assert) -> Any: ...
+    def visit_Import(self, node: Import) -> Any: ...
+    def visit_ImportFrom(self, node: ImportFrom) -> Any: ...
+    def visit_Global(self, node: Global) -> Any: ...
+    def visit_Nonlocal(self, node: Nonlocal) -> Any: ...
+    def visit_Expr(self, node: Expr) -> Any: ...
+    def visit_Pass(self, node: Pass) -> Any: ...
+    def visit_Break(self, node: Break) -> Any: ...
+    def visit_Continue(self, node: Continue) -> Any: ...
+    def visit_Slice(self, node: Slice) -> Any: ...
+    def visit_BoolOp(self, node: BoolOp) -> Any: ...
+    def visit_BinOp(self, node: BinOp) -> Any: ...
+    def visit_UnaryOp(self, node: UnaryOp) -> Any: ...
+    def visit_Lambda(self, node: Lambda) -> Any: ...
+    def visit_IfExp(self, node: IfExp) -> Any: ...
+    def visit_Dict(self, node: Dict) -> Any: ...
+    def visit_Set(self, node: Set) -> Any: ...
+    def visit_ListComp(self, node: ListComp) -> Any: ...
+    def visit_SetComp(self, node: SetComp) -> Any: ...
+    def visit_DictComp(self, node: DictComp) -> Any: ...
+    def visit_GeneratorExp(self, node: GeneratorExp) -> Any: ...
+    def visit_Await(self, node: Await) -> Any: ...
+    def visit_Yield(self, node: Yield) -> Any: ...
+    def visit_YieldFrom(self, node: YieldFrom) -> Any: ...
+    def visit_Compare(self, node: Compare) -> Any: ...
+    def visit_Call(self, node: Call) -> Any: ...
+    def visit_FormattedValue(self, node: FormattedValue) -> Any: ...
+    def visit_JoinedStr(self, node: JoinedStr) -> Any: ...
+    def visit_Constant(self, node: Constant) -> Any: ...
+    def visit_NamedExpr(self, node: NamedExpr) -> Any: ...
+    def visit_TypeIgnore(self, node: TypeIgnore) -> Any: ...
+    def visit_Attribute(self, node: Attribute) -> Any: ...
+    def visit_Subscript(self, node: Subscript) -> Any: ...
+    def visit_Starred(self, node: Starred) -> Any: ...
+    def visit_Name(self, node: Name) -> Any: ...
+    def visit_List(self, node: List) -> Any: ...
+    def visit_Tuple(self, node: Tuple) -> Any: ...
+    def visit_Del(self, node: Del) -> Any: ...
+    def visit_Load(self, node: Load) -> Any: ...
+    def visit_Store(self, node: Store) -> Any: ...
+    def visit_And(self, node: And) -> Any: ...
+    def visit_Or(self, node: Or) -> Any: ...
+    def visit_Add(self, node: Add) -> Any: ...
+    def visit_BitAnd(self, node: BitAnd) -> Any: ...
+    def visit_BitOr(self, node: BitOr) -> Any: ...
+    def visit_BitXor(self, node: BitXor) -> Any: ...
+    def visit_Div(self, node: Div) -> Any: ...
+    def visit_FloorDiv(self, node: FloorDiv) -> Any: ...
+    def visit_LShift(self, node: LShift) -> Any: ...
+    def visit_Mod(self, node: Mod) -> Any: ...
+    def visit_Mult(self, node: Mult) -> Any: ...
+    def visit_MatMult(self, node: MatMult) -> Any: ...
+    def visit_Pow(self, node: Pow) -> Any: ...
+    def visit_RShift(self, node: RShift) -> Any: ...
+    def visit_Sub(self, node: Sub) -> Any: ...
+    def visit_Invert(self, node: Invert) -> Any: ...
+    def visit_Not(self, node: Not) -> Any: ...
+    def visit_UAdd(self, node: UAdd) -> Any: ...
+    def visit_USub(self, node: USub) -> Any: ...
+    def visit_Eq(self, node: Eq) -> Any: ...
+    def visit_Gt(self, node: Gt) -> Any: ...
+    def visit_GtE(self, node: GtE) -> Any: ...
+    def visit_In(self, node: In) -> Any: ...
+    def visit_Is(self, node: Is) -> Any: ...
+    def visit_IsNot(self, node: IsNot) -> Any: ...
+    def visit_Lt(self, node: Lt) -> Any: ...
+    def visit_LtE(self, node: LtE) -> Any: ...
+    def visit_NotEq(self, node: NotEq) -> Any: ...
+    def visit_NotIn(self, node: NotIn) -> Any: ...
+    def visit_comprehension(self, node: comprehension) -> Any: ...
+    def visit_ExceptHandler(self, node: ExceptHandler) -> Any: ...
+    def visit_arguments(self, node: arguments) -> Any: ...
+    def visit_arg(self, node: arg) -> Any: ...
+    def visit_keyword(self, node: keyword) -> Any: ...
+    def visit_alias(self, node: alias) -> Any: ...
+    def visit_withitem(self, node: withitem) -> Any: ...
+    if sys.version_info >= (3, 10):
+        def visit_Match(self, node: Match) -> Any: ...
+        def visit_match_case(self, node: match_case) -> Any: ...
+        def visit_MatchValue(self, node: MatchValue) -> Any: ...
+        def visit_MatchSequence(self, node: MatchSequence) -> Any: ...
+        def visit_MatchSingleton(self, node: MatchSingleton) -> Any: ...
+        def visit_MatchStar(self, node: MatchStar) -> Any: ...
+        def visit_MatchMapping(self, node: MatchMapping) -> Any: ...
+        def visit_MatchClass(self, node: MatchClass) -> Any: ...
+        def visit_MatchAs(self, node: MatchAs) -> Any: ...
+        def visit_MatchOr(self, node: MatchOr) -> Any: ...
+
+    if sys.version_info >= (3, 11):
+        def visit_TryStar(self, node: TryStar) -> Any: ...
+
+    if sys.version_info >= (3, 12):
+        def visit_TypeVar(self, node: TypeVar) -> Any: ...
+        def visit_ParamSpec(self, node: ParamSpec) -> Any: ...
+        def visit_TypeVarTuple(self, node: TypeVarTuple) -> Any: ...
+        def visit_TypeAlias(self, node: TypeAlias) -> Any: ...
+
+    # visit methods for deprecated nodes
+    def visit_ExtSlice(self, node: ExtSlice) -> Any: ...
+    def visit_Index(self, node: Index) -> Any: ...
+    def visit_Suite(self, node: Suite) -> Any: ...
+    def visit_AugLoad(self, node: AugLoad) -> Any: ...
+    def visit_AugStore(self, node: AugStore) -> Any: ...
+    def visit_Param(self, node: Param) -> Any: ...
+    def visit_Num(self, node: Num) -> Any: ...
+    def visit_Str(self, node: Str) -> Any: ...
+    def visit_Bytes(self, node: Bytes) -> Any: ...
+    def visit_NameConstant(self, node: NameConstant) -> Any: ...
+    def visit_Ellipsis(self, node: Ellipsis) -> Any: ...
+
+class NodeTransformer(NodeVisitor):
+    def generic_visit(self, node: AST) -> AST: ...
+    # TODO: Override the visit_* methods with better return types.
+    #       The usual return type is AST | None, but Iterable[AST]
+    #       is also allowed in some cases -- this needs to be mapped.
+
+_T = _TypeVar("_T", bound=AST)
+
+if sys.version_info >= (3, 13):
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        filename: str | ReadableBuffer | os.PathLike[Any] = "<unknown>",
+        mode: Literal["exec"] = "exec",
+        *,
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+        optimize: Literal[-1, 0, 1, 2] = -1,
+    ) -> Module: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        filename: str | ReadableBuffer | os.PathLike[Any],
+        mode: Literal["eval"],
+        *,
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+        optimize: Literal[-1, 0, 1, 2] = -1,
+    ) -> Expression: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        filename: str | ReadableBuffer | os.PathLike[Any],
+        mode: Literal["func_type"],
+        *,
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+        optimize: Literal[-1, 0, 1, 2] = -1,
+    ) -> FunctionType: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        filename: str | ReadableBuffer | os.PathLike[Any],
+        mode: Literal["single"],
+        *,
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+        optimize: Literal[-1, 0, 1, 2] = -1,
+    ) -> Interactive: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        *,
+        mode: Literal["eval"],
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+        optimize: Literal[-1, 0, 1, 2] = -1,
+    ) -> Expression: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        *,
+        mode: Literal["func_type"],
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+        optimize: Literal[-1, 0, 1, 2] = -1,
+    ) -> FunctionType: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        *,
+        mode: Literal["single"],
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+        optimize: Literal[-1, 0, 1, 2] = -1,
+    ) -> Interactive: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        filename: str | ReadableBuffer | os.PathLike[Any] = "<unknown>",
+        mode: str = "exec",
+        *,
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+        optimize: Literal[-1, 0, 1, 2] = -1,
+    ) -> AST: ...
+
+else:
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        filename: str | ReadableBuffer | os.PathLike[Any] = "<unknown>",
+        mode: Literal["exec"] = "exec",
+        *,
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+    ) -> Module: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        filename: str | ReadableBuffer | os.PathLike[Any],
+        mode: Literal["eval"],
+        *,
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+    ) -> Expression: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        filename: str | ReadableBuffer | os.PathLike[Any],
+        mode: Literal["func_type"],
+        *,
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+    ) -> FunctionType: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        filename: str | ReadableBuffer | os.PathLike[Any],
+        mode: Literal["single"],
+        *,
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+    ) -> Interactive: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        *,
+        mode: Literal["eval"],
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+    ) -> Expression: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        *,
+        mode: Literal["func_type"],
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+    ) -> FunctionType: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        *,
+        mode: Literal["single"],
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+    ) -> Interactive: ...
+    @overload
+    def parse(
+        source: str | ReadableBuffer,
+        filename: str | ReadableBuffer | os.PathLike[Any] = "<unknown>",
+        mode: str = "exec",
+        *,
+        type_comments: bool = False,
+        feature_version: None | int | tuple[int, int] = None,
+    ) -> AST: ...
+
+if sys.version_info >= (3, 9):
+    def unparse(ast_obj: AST) -> str: ...
+
+def copy_location(new_node: _T, old_node: AST) -> _T: ...
+
+if sys.version_info >= (3, 13):
+    def dump(
+        node: AST,
+        annotate_fields: bool = True,
+        include_attributes: bool = False,
+        *,
+        indent: int | str | None = None,
+        show_empty: bool = False,
+    ) -> str: ...
+
+elif sys.version_info >= (3, 9):
+    def dump(
+        node: AST, annotate_fields: bool = True, include_attributes: bool = False, *, indent: int | str | None = None
+    ) -> str: ...
+
+else:
+    def dump(node: AST, annotate_fields: bool = True, include_attributes: bool = False) -> str: ...
+
+def fix_missing_locations(node: _T) -> _T: ...
+def get_docstring(node: AsyncFunctionDef | FunctionDef | ClassDef | Module, clean: bool = True) -> str | None: ...
+def increment_lineno(node: _T, n: int = 1) -> _T: ...
+def iter_child_nodes(node: AST) -> Iterator[AST]: ...
+def iter_fields(node: AST) -> Iterator[tuple[str, Any]]: ...
+def literal_eval(node_or_string: str | AST) -> Any: ...
+def get_source_segment(source: str, node: AST, *, padded: bool = False) -> str | None: ...
+def walk(node: AST) -> Iterator[AST]: ...
+
+if sys.version_info >= (3, 9):
+    def main() -> None: ...