hir_def/
dyn_map.rs

1//! This module defines a `DynMap` -- a container for heterogeneous maps.
2//!
3//! This means that `DynMap` stores a bunch of hash maps inside, and those maps
4//! can be of different types.
5//!
6//! It is used like this:
7//!
8//! ```ignore
9//! # use hir_def::dyn_map::DynMap;
10//! # use hir_def::dyn_map::Key;
11//! // keys define submaps of a `DynMap`
12//! const STRING_TO_U32: Key<String, u32> = Key::new();
13//! const U32_TO_VEC: Key<u32, Vec<bool>> = Key::new();
14//!
15//! // Note: concrete type, no type params!
16//! let mut map = DynMap::new();
17//!
18//! // To access a specific map, index the `DynMap` by `Key`:
19//! map[STRING_TO_U32].insert("hello".to_string(), 92);
20//! let value = map[U32_TO_VEC].get(92);
21//! assert!(value.is_none());
22//! ```
23//!
24//! This is a work of fiction. Any similarities to Kotlin's `BindingContext` are
25//! a coincidence.
26
27pub mod keys {
28    use std::marker::PhantomData;
29
30    use either::Either;
31    use hir_expand::{MacroCallId, attrs::AttrId};
32    use rustc_hash::FxHashMap;
33    use syntax::{AstNode, AstPtr, ast};
34
35    use crate::{
36        BlockId, BuiltinDeriveImplId, ConstId, EnumId, EnumVariantId, ExternBlockId, ExternCrateId,
37        FieldId, FunctionId, ImplId, LifetimeParamId, Macro2Id, MacroRulesId, ProcMacroId,
38        StaticId, StructId, TraitId, TypeAliasId, TypeOrConstParamId, UnionId, UseId,
39        dyn_map::{DynMap, Policy},
40    };
41
42    pub type Key<K, V> = crate::dyn_map::Key<AstPtr<K>, V, AstPtrPolicy<K, V>>;
43
44    pub const BLOCK: Key<ast::BlockExpr, BlockId> = Key::new();
45    pub const FUNCTION: Key<ast::Fn, FunctionId> = Key::new();
46    pub const CONST: Key<ast::Const, ConstId> = Key::new();
47    pub const STATIC: Key<ast::Static, StaticId> = Key::new();
48    pub const TYPE_ALIAS: Key<ast::TypeAlias, TypeAliasId> = Key::new();
49    pub const IMPL: Key<ast::Impl, ImplId> = Key::new();
50    pub const EXTERN_BLOCK: Key<ast::ExternBlock, ExternBlockId> = Key::new();
51    pub const TRAIT: Key<ast::Trait, TraitId> = Key::new();
52    pub const STRUCT: Key<ast::Struct, StructId> = Key::new();
53    pub const UNION: Key<ast::Union, UnionId> = Key::new();
54    pub const ENUM: Key<ast::Enum, EnumId> = Key::new();
55    pub const EXTERN_CRATE: Key<ast::ExternCrate, ExternCrateId> = Key::new();
56    pub const USE: Key<ast::Use, UseId> = Key::new();
57
58    pub const ENUM_VARIANT: Key<ast::Variant, EnumVariantId> = Key::new();
59    pub const TUPLE_FIELD: Key<ast::TupleField, FieldId> = Key::new();
60    pub const RECORD_FIELD: Key<ast::RecordField, FieldId> = Key::new();
61    pub const TYPE_PARAM: Key<ast::TypeParam, TypeOrConstParamId> = Key::new();
62    pub const CONST_PARAM: Key<ast::ConstParam, TypeOrConstParamId> = Key::new();
63    pub const LIFETIME_PARAM: Key<ast::LifetimeParam, LifetimeParamId> = Key::new();
64
65    pub const MACRO_RULES: Key<ast::MacroRules, MacroRulesId> = Key::new();
66    pub const MACRO2: Key<ast::MacroDef, Macro2Id> = Key::new();
67    pub const PROC_MACRO: Key<ast::Fn, ProcMacroId> = Key::new();
68    pub const MACRO_CALL: Key<ast::MacroCall, MacroCallId> = Key::new();
69    pub const ATTR_MACRO_CALL: Key<ast::Item, MacroCallId> = Key::new();
70    pub const DERIVE_MACRO_CALL: Key<
71        ast::Meta,
72        (
73            AttrId,
74            /* derive() */ MacroCallId,
75            /* actual derive macros */
76            Box<[Option<Either<MacroCallId, BuiltinDeriveImplId>>]>,
77        ),
78    > = Key::new();
79
80    /// XXX: AST Nodes and SyntaxNodes have identity equality semantics: nodes are
81    /// equal if they point to exactly the same object.
82    ///
83    /// In general, we do not guarantee that we have exactly one instance of a
84    /// syntax tree for each file. We probably should add such guarantee, but, for
85    /// the time being, we will use identity-less AstPtr comparison.
86    pub struct AstPtrPolicy<AST, ID> {
87        _phantom: PhantomData<(AST, ID)>,
88    }
89
90    impl<AST: AstNode + 'static, ID: 'static> Policy for AstPtrPolicy<AST, ID> {
91        type K = AstPtr<AST>;
92        type V = ID;
93        fn insert(map: &mut DynMap, key: AstPtr<AST>, value: ID) {
94            map.map
95                .entry::<FxHashMap<AstPtr<AST>, ID>>()
96                .or_insert_with(Default::default)
97                .insert(key, value);
98        }
99        fn get<'a>(map: &'a DynMap, key: &AstPtr<AST>) -> Option<&'a ID> {
100            map.map.get::<FxHashMap<AstPtr<AST>, ID>>()?.get(key)
101        }
102        fn is_empty(map: &DynMap) -> bool {
103            map.map.get::<FxHashMap<AstPtr<AST>, ID>>().is_none_or(|it| it.is_empty())
104        }
105    }
106}
107
108use std::{
109    hash::Hash,
110    marker::PhantomData,
111    ops::{Index, IndexMut},
112};
113
114use rustc_hash::FxHashMap;
115use stdx::anymap::Map;
116
117pub struct Key<K, V, P = (K, V)> {
118    _phantom: PhantomData<(K, V, P)>,
119}
120
121impl<K, V, P> Key<K, V, P> {
122    pub(crate) const fn new() -> Key<K, V, P> {
123        Key { _phantom: PhantomData }
124    }
125}
126
127impl<K, V, P> Copy for Key<K, V, P> {}
128
129impl<K, V, P> Clone for Key<K, V, P> {
130    fn clone(&self) -> Key<K, V, P> {
131        *self
132    }
133}
134
135pub trait Policy {
136    type K;
137    type V;
138
139    fn insert(map: &mut DynMap, key: Self::K, value: Self::V);
140    fn get<'a>(map: &'a DynMap, key: &Self::K) -> Option<&'a Self::V>;
141    fn is_empty(map: &DynMap) -> bool;
142}
143
144impl<K: Hash + Eq + 'static, V: 'static> Policy for (K, V) {
145    type K = K;
146    type V = V;
147    fn insert(map: &mut DynMap, key: K, value: V) {
148        map.map.entry::<FxHashMap<K, V>>().or_insert_with(Default::default).insert(key, value);
149    }
150    fn get<'a>(map: &'a DynMap, key: &K) -> Option<&'a V> {
151        map.map.get::<FxHashMap<K, V>>()?.get(key)
152    }
153    fn is_empty(map: &DynMap) -> bool {
154        map.map.get::<FxHashMap<K, V>>().is_none_or(|it| it.is_empty())
155    }
156}
157
158#[derive(Default)]
159pub struct DynMap {
160    pub(crate) map: Map,
161}
162
163#[repr(transparent)]
164pub struct KeyMap<KEY> {
165    map: DynMap,
166    _phantom: PhantomData<KEY>,
167}
168
169impl<P: Policy> KeyMap<Key<P::K, P::V, P>> {
170    pub fn insert(&mut self, key: P::K, value: P::V) {
171        P::insert(&mut self.map, key, value)
172    }
173    pub fn get(&self, key: &P::K) -> Option<&P::V> {
174        P::get(&self.map, key)
175    }
176
177    pub fn is_empty(&self) -> bool {
178        P::is_empty(&self.map)
179    }
180}
181
182impl<P: Policy> Index<Key<P::K, P::V, P>> for DynMap {
183    type Output = KeyMap<Key<P::K, P::V, P>>;
184    fn index(&self, _key: Key<P::K, P::V, P>) -> &Self::Output {
185        // Safe due to `#[repr(transparent)]`.
186        unsafe { std::mem::transmute::<&DynMap, &KeyMap<Key<P::K, P::V, P>>>(self) }
187    }
188}
189
190impl<P: Policy> IndexMut<Key<P::K, P::V, P>> for DynMap {
191    fn index_mut(&mut self, _key: Key<P::K, P::V, P>) -> &mut Self::Output {
192        // Safe due to `#[repr(transparent)]`.
193        unsafe { std::mem::transmute::<&mut DynMap, &mut KeyMap<Key<P::K, P::V, P>>>(self) }
194    }
195}
hir_def/dyn_map.rs

hir_def/
dyn_map.rs
