Introduce ruff_index crate (#4597)

crates/ruff_python_semantic/src/binding.rs

@@ -1,8 +1,8 @@
-use std::num::TryFromIntError;
-use std::ops::{Deref, Index, IndexMut};
+use std::ops::{Deref, DerefMut};
 
 use crate::model::SemanticModel;
 use bitflags::bitflags;
+use ruff_index::{newtype_index, IndexSlice, IndexVec};
 use ruff_python_ast::helpers;
 use ruff_python_ast::source_code::Locator;
 use ruff_text_size::TextRange;
@@ -130,16 +130,8 @@ impl<'a> Binding<'a> {
 /// Using a `u32` to identify [Binding]s should is sufficient because Ruff only supports documents with a
 /// size smaller than or equal to `u32::max`. A document with the size of `u32::max` must have fewer than `u32::max`
 /// bindings because bindings must be separated by whitespace (and have an assignment).
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
-pub struct BindingId(u32);
-
-impl TryFrom<usize> for BindingId {
-    type Error = TryFromIntError;
-
-    fn try_from(value: usize) -> Result<Self, Self::Error> {
-        Ok(Self(u32::try_from(value)?))
-    }
-}
+#[newtype_index]
+pub struct BindingId;
 
 impl nohash_hasher::IsEnabled for BindingId {}
 
@@ -147,53 +139,37 @@ impl nohash_hasher::IsEnabled for BindingId {}
 ///
 /// Bindings are indexed by [`BindingId`]
 #[derive(Debug, Clone, Default)]
-pub struct Bindings<'a>(Vec<Binding<'a>>);
+pub struct Bindings<'a>(IndexVec<BindingId, Binding<'a>>);
 
 impl<'a> Bindings<'a> {
     /// Pushes a new binding and returns its id
     pub fn push(&mut self, binding: Binding<'a>) -> BindingId {
-        let id = self.next_id();
-        self.0.push(binding);
-        id
+        self.0.push(binding)
     }
 
     /// Returns the id that will be assigned when pushing the next binding
     pub fn next_id(&self) -> BindingId {
-        BindingId::try_from(self.0.len()).unwrap()
-    }
-}
-
-impl<'a> Index<BindingId> for Bindings<'a> {
-    type Output = Binding<'a>;
-
-    fn index(&self, index: BindingId) -> &Self::Output {
-        &self.0[usize::from(index)]
-    }
-}
-
-impl<'a> IndexMut<BindingId> for Bindings<'a> {
-    fn index_mut(&mut self, index: BindingId) -> &mut Self::Output {
-        &mut self.0[usize::from(index)]
+        self.0.next_index()
     }
 }
 
 impl<'a> Deref for Bindings<'a> {
-    type Target = [Binding<'a>];
+    type Target = IndexSlice<BindingId, Binding<'a>>;
 
     fn deref(&self) -> &Self::Target {
         &self.0
     }
 }
 
-impl<'a> FromIterator<Binding<'a>> for Bindings<'a> {
-    fn from_iter<T: IntoIterator<Item = Binding<'a>>>(iter: T) -> Self {
-        Self(Vec::from_iter(iter))
+impl<'a> DerefMut for Bindings<'a> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
     }
 }
 
-impl From<BindingId> for usize {
-    fn from(value: BindingId) -> Self {
-        value.0 as usize
+impl<'a> FromIterator<Binding<'a>> for Bindings<'a> {
+    fn from_iter<T: IntoIterator<Item = Binding<'a>>>(iter: T) -> Self {
+        Self(IndexVec::from_iter(iter))
     }
 }
 

crates/ruff_python_semantic/src/definition.rs

@@ -2,9 +2,9 @@
 //! can be documented, such as a module, class, or function.
 
 use std::fmt::Debug;
-use std::num::TryFromIntError;
-use std::ops::{Deref, Index};
+use std::ops::Deref;
 
+use ruff_index::{newtype_index, IndexSlice, IndexVec};
 use rustpython_parser::ast::{self, Stmt};
 
 use crate::analyze::visibility::{
@@ -12,28 +12,14 @@ use crate::analyze::visibility::{
 };
 
 /// Id uniquely identifying a definition in a program.
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Ord, PartialOrd)]
-pub struct DefinitionId(u32);
+#[newtype_index]
+pub struct DefinitionId;
 
 impl DefinitionId {
     /// Returns the ID for the module definition.
     #[inline]
     pub const fn module() -> Self {
-        DefinitionId(0)
-    }
-}
-
-impl TryFrom<usize> for DefinitionId {
-    type Error = TryFromIntError;
-
-    fn try_from(value: usize) -> Result<Self, Self::Error> {
-        Ok(Self(u32::try_from(value)?))
-    }
-}
-
-impl From<DefinitionId> for usize {
-    fn from(value: DefinitionId) -> Self {
-        value.0 as usize
+        DefinitionId::from_u32(0)
     }
 }
 
@@ -118,11 +104,11 @@ impl Definition<'_> {
 
 /// The definitions within a Python program indexed by [`DefinitionId`].
 #[derive(Debug, Default)]
-pub struct Definitions<'a>(Vec<Definition<'a>>);
+pub struct Definitions<'a>(IndexVec<DefinitionId, Definition<'a>>);
 
 impl<'a> Definitions<'a> {
     pub fn for_module(definition: Module<'a>) -> Self {
-        Self(vec![Definition::Module(definition)])
+        Self(IndexVec::from_raw(vec![Definition::Module(definition)]))
     }
 
     /// Pushes a new member definition and returns its unique id.
@@ -130,14 +116,13 @@ impl<'a> Definitions<'a> {
     /// Members are assumed to be pushed in traversal order, such that parents are pushed before
     /// their children.
     pub fn push_member(&mut self, member: Member<'a>) -> DefinitionId {
-        let next_id = DefinitionId::try_from(self.0.len()).unwrap();
-        self.0.push(Definition::Member(member));
-        next_id
+        self.0.push(Definition::Member(member))
     }
 
     /// Resolve the visibility of each definition in the collection.
     pub fn resolve(self, exports: Option<&[&str]>) -> ContextualizedDefinitions<'a> {
-        let mut definitions: Vec<ContextualizedDefinition<'a>> = Vec::with_capacity(self.len());
+        let mut definitions: IndexVec<DefinitionId, ContextualizedDefinition<'a>> =
+            IndexVec::with_capacity(self.len());
 
         for definition in self {
             // Determine the visibility of the next definition, taking into account its parent's
@@ -147,7 +132,7 @@ impl<'a> Definitions<'a> {
                     Definition::Module(module) => module.source.to_visibility(),
                     Definition::Member(member) => match member.kind {
                         MemberKind::Class => {
-                            let parent = &definitions[usize::from(member.parent)];
+                            let parent = &definitions[member.parent];
                             if parent.visibility.is_private()
                                 || exports
                                     .map_or(false, |exports| !exports.contains(&member.name()))
@@ -158,7 +143,7 @@ impl<'a> Definitions<'a> {
                             }
                         }
                         MemberKind::NestedClass => {
-                            let parent = &definitions[usize::from(member.parent)];
+                            let parent = &definitions[member.parent];
                             if parent.visibility.is_private()
                                 || matches!(
                                     parent.definition,
@@ -176,7 +161,7 @@ impl<'a> Definitions<'a> {
                             }
                         }
                         MemberKind::Function => {
-                            let parent = &definitions[usize::from(member.parent)];
+                            let parent = &definitions[member.parent];
                             if parent.visibility.is_private()
                                 || exports
                                     .map_or(false, |exports| !exports.contains(&member.name()))
@@ -188,7 +173,7 @@ impl<'a> Definitions<'a> {
                         }
                         MemberKind::NestedFunction => Visibility::Private,
                         MemberKind::Method => {
-                            let parent = &definitions[usize::from(member.parent)];
+                            let parent = &definitions[member.parent];
                             if parent.visibility.is_private() {
                                 Visibility::Private
                             } else {
@@ -204,20 +189,13 @@ impl<'a> Definitions<'a> {
             });
         }
 
-        ContextualizedDefinitions(definitions)
-    }
-}
-
-impl<'a> Index<DefinitionId> for Definitions<'a> {
-    type Output = Definition<'a>;
-
-    fn index(&self, index: DefinitionId) -> &Self::Output {
-        &self.0[usize::from(index)]
+        ContextualizedDefinitions(definitions.raw)
     }
 }
 
 impl<'a> Deref for Definitions<'a> {
-    type Target = [Definition<'a>];
+    type Target = IndexSlice<DefinitionId, Definition<'a>>;
+
     fn deref(&self) -> &Self::Target {
         &self.0
     }

crates/ruff_python_semantic/src/node.rs

@@ -1,6 +1,6 @@
-use std::num::{NonZeroU32, TryFromIntError};
 use std::ops::{Index, IndexMut};
 
+use ruff_index::{newtype_index, IndexVec};
 use rustc_hash::FxHashMap;
 use rustpython_parser::ast::Stmt;
 
@@ -11,24 +11,9 @@ use ruff_python_ast::types::RefEquality;
 /// Using a `u32` is sufficient because Ruff only supports parsing documents with a size of max `u32::max`
 /// and it is impossible to have more statements than characters in the file. We use a `NonZeroU32` to
 /// take advantage of memory layout optimizations.
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Ord, PartialOrd)]
-pub struct NodeId(NonZeroU32);
-
-/// Convert a `usize` to a `NodeId` (by adding 1 to the value, and casting to `NonZeroU32`).
-impl TryFrom<usize> for NodeId {
-    type Error = TryFromIntError;
-
-    fn try_from(value: usize) -> Result<Self, Self::Error> {
-        Ok(Self(NonZeroU32::try_from(u32::try_from(value)? + 1)?))
-    }
-}
-
-/// Convert a `NodeId` to a `usize` (by subtracting 1 from the value, and casting to `usize`).
-impl From<NodeId> for usize {
-    fn from(value: NodeId) -> Self {
-        value.0.get() as usize - 1
-    }
-}
+#[newtype_index]
+#[derive(Ord, PartialOrd)]
+pub struct NodeId;
 
 /// A [`Node`] represents a statement in a program, along with a pointer to its parent (if any).
 #[derive(Debug)]
@@ -44,7 +29,7 @@ struct Node<'a> {
 /// The nodes of a program indexed by [`NodeId`]
 #[derive(Debug, Default)]
 pub struct Nodes<'a> {
-    nodes: Vec<Node<'a>>,
+    nodes: IndexVec<NodeId, Node<'a>>,
     node_to_id: FxHashMap<RefEquality<'a, Stmt>, NodeId>,
 }
 
@@ -53,16 +38,15 @@ impl<'a> Nodes<'a> {
     ///
     /// Panics if a node with the same pointer already exists.
     pub fn insert(&mut self, stmt: &'a Stmt, parent: Option<NodeId>) -> NodeId {
-        let next_id = NodeId::try_from(self.nodes.len()).unwrap();
+        let next_id = self.nodes.next_index();
         if let Some(existing_id) = self.node_to_id.insert(RefEquality(stmt), next_id) {
             panic!("Node already exists with id {existing_id:?}");
         }
         self.nodes.push(Node {
             stmt,
             parent,
-            depth: parent.map_or(0, |parent| self.nodes[usize::from(parent)].depth + 1),
-        });
-        next_id
+            depth: parent.map_or(0, |parent| self.nodes[parent].depth + 1),
+        })
     }
 
     /// Returns the [`NodeId`] of the given node.
@@ -74,26 +58,24 @@ impl<'a> Nodes<'a> {
     /// Return the [`NodeId`] of the parent node.
     #[inline]
     pub fn parent_id(&self, node_id: NodeId) -> Option<NodeId> {
-        self.nodes[usize::from(node_id)].parent
+        self.nodes[node_id].parent
     }
 
     /// Return the depth of the node.
     #[inline]
     pub fn depth(&self, node_id: NodeId) -> u32 {
-        self.nodes[usize::from(node_id)].depth
+        self.nodes[node_id].depth
     }
 
     /// Returns an iterator over all [`NodeId`] ancestors, starting from the given [`NodeId`].
     pub fn ancestor_ids(&self, node_id: NodeId) -> impl Iterator<Item = NodeId> + '_ {
-        std::iter::successors(Some(node_id), |&node_id| {
-            self.nodes[usize::from(node_id)].parent
-        })
+        std::iter::successors(Some(node_id), |&node_id| self.nodes[node_id].parent)
     }
 
     /// Return the parent of the given node.
     pub fn parent(&self, node: &'a Stmt) -> Option<&'a Stmt> {
         let node_id = self.node_to_id.get(&RefEquality(node))?;
-        let parent_id = self.nodes[usize::from(*node_id)].parent?;
+        let parent_id = self.nodes[*node_id].parent?;
         Some(self[parent_id])
     }
 }
@@ -101,13 +83,15 @@ impl<'a> Nodes<'a> {
 impl<'a> Index<NodeId> for Nodes<'a> {
     type Output = &'a Stmt;
 
+    #[inline]
     fn index(&self, index: NodeId) -> &Self::Output {
-        &self.nodes[usize::from(index)].stmt
+        &self.nodes[index].stmt
     }
 }
 
 impl<'a> IndexMut<NodeId> for Nodes<'a> {
+    #[inline]
     fn index_mut(&mut self, index: NodeId) -> &mut Self::Output {
-        &mut self.nodes[usize::from(index)].stmt
+        &mut self.nodes[index].stmt
     }
 }

crates/ruff_python_semantic/src/scope.rs

@@ -1,6 +1,6 @@
-use std::num::TryFromIntError;
-use std::ops::{Deref, Index, IndexMut};
+use std::ops::{Deref, DerefMut};
 
+use ruff_index::{newtype_index, Idx, IndexSlice, IndexVec};
 use rustc_hash::FxHashMap;
 use rustpython_parser::ast::{Arguments, Expr, Keyword, Stmt};
 
@@ -151,39 +151,25 @@ pub struct Lambda<'a> {
 /// Using a `u32` is sufficient because Ruff only supports parsing documents with a size of max `u32::max`
 /// and it is impossible to have more scopes than characters in the file (because defining a function or class
 /// requires more than one character).
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Ord, PartialOrd)]
-pub struct ScopeId(u32);
+#[newtype_index]
+pub struct ScopeId;
 
 impl ScopeId {
     /// Returns the ID for the global scope
     #[inline]
     pub const fn global() -> Self {
-        ScopeId(0)
+        ScopeId::from_u32(0)
     }
 
     /// Returns `true` if this is the id of the global scope
     pub const fn is_global(&self) -> bool {
-        self.0 == 0
-    }
-}
-
-impl TryFrom<usize> for ScopeId {
-    type Error = TryFromIntError;
-
-    fn try_from(value: usize) -> Result<Self, Self::Error> {
-        Ok(Self(u32::try_from(value)?))
-    }
-}
-
-impl From<ScopeId> for usize {
-    fn from(value: ScopeId) -> Self {
-        value.0 as usize
+        self.index() == 0
     }
 }
 
 /// The scopes of a program indexed by [`ScopeId`]
 #[derive(Debug)]
-pub struct Scopes<'a>(Vec<Scope<'a>>);
+pub struct Scopes<'a>(IndexVec<ScopeId, Scope<'a>>);
 
 impl<'a> Scopes<'a> {
     /// Returns a reference to the global scope
@@ -198,7 +184,7 @@ impl<'a> Scopes<'a> {
 
     /// Pushes a new scope and returns its unique id
     pub fn push_scope(&mut self, kind: ScopeKind<'a>, parent: ScopeId) -> ScopeId {
-        let next_id = ScopeId::try_from(self.0.len()).unwrap();
+        let next_id = ScopeId::new(self.0.len());
         self.0.push(Scope::local(kind, parent));
         next_id
     }
@@ -218,27 +204,19 @@ impl<'a> Scopes<'a> {
 
 impl Default for Scopes<'_> {
     fn default() -> Self {
-        Self(vec![Scope::global()])
-    }
-}
-
-impl<'a> Index<ScopeId> for Scopes<'a> {
-    type Output = Scope<'a>;
-
-    fn index(&self, index: ScopeId) -> &Self::Output {
-        &self.0[usize::from(index)]
-    }
-}
-
-impl<'a> IndexMut<ScopeId> for Scopes<'a> {
-    fn index_mut(&mut self, index: ScopeId) -> &mut Self::Output {
-        &mut self.0[usize::from(index)]
+        Self(IndexVec::from_raw(vec![Scope::global()]))
     }
 }
 
 impl<'a> Deref for Scopes<'a> {
-    type Target = [Scope<'a>];
+    type Target = IndexSlice<ScopeId, Scope<'a>>;
     fn deref(&self) -> &Self::Target {
         &self.0
     }
 }
+
+impl<'a> DerefMut for Scopes<'a> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}