(Supersedes #9152, authored by @LaBatata101)
## Summary
This PR replaces the current parser generated from LALRPOP to a
hand-written recursive descent parser.
It also updates the grammar for [PEP
646](https://peps.python.org/pep-0646/) so that the parser outputs the
correct AST. For example, in `data[*x]`, the index expression is now a
tuple with a single starred expression instead of just a starred
expression.
Beyond the performance improvements, the parser is also error resilient
and can provide better error messages. The behavior as seen by any
downstream tools isn't changed. That is, the linter and formatter can
still assume that the parser will _stop_ at the first syntax error. This
will be updated in the following months.
For more details about the change here, refer to the PR corresponding to
the individual commits and the release blog post.
## Test Plan
Write _lots_ and _lots_ of tests for both valid and invalid syntax and
verify the output.
## Acknowledgements
- @MichaReiser for reviewing 100+ parser PRs and continuously providing
guidance throughout the project
- @LaBatata101 for initiating the transition to a hand-written parser in
#9152
- @addisoncrump for implementing the fuzzer which helped
[catch](https://github.com/astral-sh/ruff/pull/10903)
[a](https://github.com/astral-sh/ruff/pull/10910)
[lot](https://github.com/astral-sh/ruff/pull/10966)
[of](https://github.com/astral-sh/ruff/pull/10896)
[bugs](https://github.com/astral-sh/ruff/pull/10877)
---------
Co-authored-by: Victor Hugo Gomes <labatata101@linuxmail.org>
Co-authored-by: Micha Reiser <micha@reiser.io>
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## Summary
Our `SoftKeywordTokenizer` only respected soft keywords in compound
statement positions -- for example, at the start of a logical line:
```python
type X = int
```
However, type aliases can also appear in simple statement positions,
like:
```python
class Class: type X = int
```
(Note that `match` and `case` are _not_ valid keywords in such
positions.)
This PR upgrades the tokenizer to track both kinds of valid positions.
Closes https://github.com/astral-sh/ruff/issues/8900.
Closes https://github.com/astral-sh/ruff/issues/8899.
## Test Plan
`cargo test`
## Summary
This PR fixes the bug in the lexer where the `Mode::Ipython` wasn't
being considered when initializing the soft keyword transformer which
wraps the lexer. This means that if the source code starts with either
`match` or `type` keyword, then the keywords were being considered as
name tokens instead. For example,
```python
match foo:
case bar:
pass
```
This would transform the `match` keyword into an identifier if the mode
is `Ipython`.
The fix is to reverse the condition in the soft keyword initializer so
that any new modes are by default considered as the lexer being at start
of line.
## Test Plan
Add a new test case for `Mode::Ipython` and verify the snapshot.
fixes: #8870
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## Summary
This PR removes the `Interactive` and `FunctionType` parser modes that are unused by ruff
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
`cargo test`
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