WIP

crates/ruff_linter/src/checkers/ast/mod.rs

@@ -43,6 +43,7 @@ use ruff_python_ast::helpers::{
     collect_import_from_member, extract_handled_exceptions, is_docstring_stmt, to_module_path,
 };
 use ruff_python_ast::identifier::Identifier;
+use ruff_python_ast::name::QualifiedName;
 use ruff_python_ast::str::trailing_quote;
 use ruff_python_ast::visitor::{walk_except_handler, walk_f_string_element, walk_pattern, Visitor};
 use ruff_python_ast::{helpers, str, visitor, PySourceType};
@@ -418,7 +419,7 @@ impl<'a> Visitor<'a> for Checker<'a> {
                     self.semantic.add_module(module);
 
                     if alias.asname.is_none() && alias.name.contains('.') {
-                        let qualified_name: Box<[&str]> = alias.name.split('.').collect();
+                        let qualified_name = QualifiedName::imported(&alias.name);
                         self.add_binding(
                             module,
                             alias.identifier(),
@@ -439,7 +440,7 @@ impl<'a> Visitor<'a> for Checker<'a> {
                         }
 
                         let name = alias.asname.as_ref().unwrap_or(&alias.name);
-                        let qualified_name: Box<[&str]> = alias.name.split('.').collect();
+                        let qualified_name = QualifiedName::imported(&alias.name);
                         self.add_binding(
                             name,
                             alias.identifier(),
@@ -503,8 +504,7 @@ impl<'a> Visitor<'a> for Checker<'a> {
                         // Attempt to resolve any relative imports; but if we don't know the current
                         // module path, or the relative import extends beyond the package root,
                         // fallback to a literal representation (e.g., `[".", "foo"]`).
-                        let qualified_name = collect_import_from_member(level, module, &alias.name)
-                            .into_boxed_slice();
+                        let qualified_name = collect_import_from_member(level, module, &alias.name);
                         self.add_binding(
                             name,
                             alias.identifier(),

crates/ruff_linter/src/renamer.rs

@@ -232,7 +232,7 @@ impl Renamer {
             }
             BindingKind::SubmoduleImport(import) => {
                 // Ex) Rename `import pandas.core` to `import pandas as pd`.
-                let module_name = import.qualified_name.first().unwrap();
+                let module_name = import.qualified_name.segments().first().unwrap();
                 Some(Edit::range_replacement(
                     format!("{module_name} as {target}"),
                     binding.range(),

crates/ruff_python_semantic/src/binding.rs

@@ -4,7 +4,7 @@ use std::ops::{Deref, DerefMut};
 use bitflags::bitflags;
 
 use ruff_index::{newtype_index, IndexSlice, IndexVec};
-use ruff_python_ast::name::format_qualified_name_segments;
+use ruff_python_ast::name::{format_qualified_name_segments, QualifiedName};
 use ruff_python_ast::Stmt;
 use ruff_source_file::Locator;
 use ruff_text_size::{Ranged, TextRange};
@@ -362,7 +362,7 @@ pub struct Import<'a> {
     /// The full name of the module being imported.
     /// Ex) Given `import foo`, `qualified_name` would be "foo".
     /// Ex) Given `import foo as bar`, `qualified_name` would be "foo".
-    pub qualified_name: Box<[&'a str]>,
+    pub qualified_name: QualifiedName<'a>,
 }
 
 /// A binding for a member imported from a module, keyed on the name to which the member is bound.
@@ -373,7 +373,7 @@ pub struct FromImport<'a> {
     /// The full name of the member being imported.
     /// Ex) Given `from foo import bar`, `qualified_name` would be "foo.bar".
     /// Ex) Given `from foo import bar as baz`, `qualified_name` would be "foo.bar".
-    pub qualified_name: Box<[&'a str]>,
+    pub qualified_name: QualifiedName<'a>,
 }
 
 /// A binding for a submodule imported from a module, keyed on the name of the parent module.
@@ -382,7 +382,7 @@ pub struct FromImport<'a> {
 pub struct SubmoduleImport<'a> {
     /// The full name of the submodule being imported.
     /// Ex) Given `import foo.bar`, `qualified_name` would be "foo.bar".
-    pub qualified_name: Box<[&'a str]>,
+    pub qualified_name: QualifiedName<'a>,
 }
 
 #[derive(Debug, Clone, is_macro::Is)]
@@ -569,12 +569,12 @@ pub trait Imported<'a> {
 impl<'a> Imported<'a> for Import<'a> {
     /// For example, given `import foo`, returns `["foo"]`.
     fn call_path(&self) -> &[&'a str] {
-        self.qualified_name.as_ref()
+        self.qualified_name.segments()
     }
 
     /// For example, given `import foo`, returns `["foo"]`.
     fn module_name(&self) -> &[&'a str] {
-        &self.qualified_name[..1]
+        &self.qualified_name.segments()[..1]
     }
 
     /// For example, given `import foo`, returns `"foo"`.
@@ -586,12 +586,12 @@ impl<'a> Imported<'a> for Import<'a> {
 impl<'a> Imported<'a> for SubmoduleImport<'a> {
     /// For example, given `import foo.bar`, returns `["foo", "bar"]`.
     fn call_path(&self) -> &[&'a str] {
-        self.qualified_name.as_ref()
+        self.qualified_name.segments()
     }
 
     /// For example, given `import foo.bar`, returns `["foo"]`.
     fn module_name(&self) -> &[&'a str] {
-        &self.qualified_name[..1]
+        &self.qualified_name.segments()[..1]
     }
 
     /// For example, given `import foo.bar`, returns `"foo.bar"`.
@@ -603,17 +603,17 @@ impl<'a> Imported<'a> for SubmoduleImport<'a> {
 impl<'a> Imported<'a> for FromImport<'a> {
     /// For example, given `from foo import bar`, returns `["foo", "bar"]`.
     fn call_path(&self) -> &[&'a str] {
-        &self.qualified_name
+        self.qualified_name.segments()
     }
 
     /// For example, given `from foo import bar`, returns `["foo"]`.
     fn module_name(&self) -> &[&'a str] {
-        &self.qualified_name[..self.qualified_name.len() - 1]
+        &self.qualified_name.segments()[..self.qualified_name.segments().len() - 1]
     }
 
     /// For example, given `from foo import bar`, returns `"bar"`.
     fn member_name(&self) -> Cow<'a, str> {
-        Cow::Borrowed(self.qualified_name[self.qualified_name.len() - 1])
+        Cow::Borrowed(self.qualified_name.segments()[self.qualified_name.segments().len() - 1])
     }
 }
 

crates/ruff_python_semantic/src/model.rs

@@ -25,6 +25,9 @@ use crate::reference::{
 use crate::scope::{Scope, ScopeId, ScopeKind, Scopes};
 use crate::Imported;
 
+// pub trait Captures<U> {}
+// impl<T: ?Sized, U> Captures<U> for T {}
+
 /// A semantic model for a Python module, to enable querying the module's semantic information.
 pub struct SemanticModel<'a> {
     typing_modules: &'a [String],
@@ -692,8 +695,12 @@ impl<'a> SemanticModel<'a> {
             BindingKind::Import(Import { qualified_name }) => {
                 let unqualified_name = UnqualifiedName::from_expr(value)?;
                 let (_, tail) = unqualified_name.segments().split_first()?;
-                let resolved: QualifiedName =
-                    qualified_name.iter().chain(tail.iter()).copied().collect();
+                let resolved: QualifiedName = qualified_name
+                    .segments()
+                    .iter()
+                    .chain(tail.iter())
+                    .copied()
+                    .collect();
                 Some(resolved)
             }
             BindingKind::SubmoduleImport(SubmoduleImport { qualified_name }) => {
@@ -702,6 +709,7 @@ impl<'a> SemanticModel<'a> {
 
                 Some(
                     qualified_name
+                        .segments()
                         .iter()
                         .take(1)
                         .chain(tail.iter())
@@ -714,12 +722,18 @@ impl<'a> SemanticModel<'a> {
                 let (_, tail) = value_name.segments().split_first()?;
 
                 let resolved: QualifiedName = if qualified_name
+                    .segments()
                     .first()
                     .map_or(false, |segment| *segment == ".")
                 {
-                    from_relative_import(self.module_path?, qualified_name, tail)?
+                    from_relative_import(self.module_path?, qualified_name.segments(), tail)?
                 } else {
-                    qualified_name.iter().chain(tail.iter()).copied().collect()
+                    qualified_name
+                        .segments()
+                        .iter()
+                        .chain(tail.iter())
+                        .copied()
+                        .collect()
                 };
                 Some(resolved)
             }
@@ -780,7 +794,7 @@ impl<'a> SemanticModel<'a> {
                         // `import sys`         -> `sys.exit`
                         // `import sys as sys2` -> `sys2.exit`
                         BindingKind::Import(Import { qualified_name }) => {
-                            if qualified_name.as_ref() == module_path.as_slice() {
+                            if qualified_name.segments() == module_path.as_slice() {
                                 if let Some(source) = binding.source {
                                     // Verify that `sys` isn't bound in an inner scope.
                                     if self
@@ -803,7 +817,7 @@ impl<'a> SemanticModel<'a> {
                         // `from os.path import join as join2` -> `join2`
                         BindingKind::FromImport(FromImport { qualified_name }) => {
                             if let Some((target_member, target_module)) =
-                                qualified_name.split_last()
+                                qualified_name.segments().split_last()
                             {
                                 if target_module == module_path.as_slice()
                                     && target_member == &member
@@ -831,7 +845,7 @@ impl<'a> SemanticModel<'a> {
                         // Ex) Given `module="os.path"` and `object="join"`:
                         // `import os.path ` -> `os.path.join`
                         BindingKind::SubmoduleImport(SubmoduleImport { qualified_name }) => {
-                            if qualified_name.starts_with(&module_path) {
+                            if qualified_name.segments().starts_with(&module_path) {
                                 if let Some(source) = binding.source {
                                     // Verify that `os` isn't bound in an inner scope.
                                     if self
@@ -959,6 +973,7 @@ impl<'a> SemanticModel<'a> {
     /// Returns an [`Iterator`] over the current statement hierarchy represented as [`NodeId`],
     /// from the current [`NodeId`] through to any parents.
     pub fn current_statement_ids(&self) -> impl Iterator<Item = NodeId> + '_ {
+        // ) -> impl Iterator<Item = NodeId> + Captures<(&'a (), &'_ ())> {
         self.node_id
             .iter()
             .flat_map(|id| self.nodes.ancestor_ids(*id))
@@ -1555,6 +1570,7 @@ impl<'a> SemanticModel<'a> {
         scope_id: ScopeId,
         binding_id: BindingId,
     ) -> impl Iterator<Item = ShadowedBinding> + '_ {
+        // ) -> impl Iterator<Item = ShadowedBinding> + Captures<(&'a (), &'_ ())> {
         let mut first = true;
         let mut binding_id = binding_id;
         std::iter::from_fn(move || {