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author | bors[bot] <bors[bot]@users.noreply.github.com> | 2018-12-29 19:31:32 +0000 |
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committer | bors[bot] <bors[bot]@users.noreply.github.com> | 2018-12-29 19:31:32 +0000 |
commit | 7fe32938b672d1fb9668b29061ac47b90f1ba599 (patch) | |
tree | d624a2b4ad749517f7946f28ad1d2874867e2032 | |
parent | 4a3d6aa26a1c71dadc91f37f9d5f8662b51c138a (diff) | |
parent | 4142792d1fd21a512d1dd37d5822ac2ba470c547 (diff) |
Merge #359
359: Add more docs in ty.rs r=matklad a=flodiebold
Also get rid of the indirection through query_definitions for the type-related
queries.
Co-authored-by: Florian Diebold <[email protected]>
-rw-r--r-- | crates/ra_hir/src/db.rs | 6 | ||||
-rw-r--r-- | crates/ra_hir/src/query_definitions.rs | 14 | ||||
-rw-r--r-- | crates/ra_hir/src/ty.rs | 77 |
3 files changed, 61 insertions, 36 deletions
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs index b41a7429a..5a8ca3b47 100644 --- a/crates/ra_hir/src/db.rs +++ b/crates/ra_hir/src/db.rs | |||
@@ -36,17 +36,17 @@ pub trait HirDatabase: SyntaxDatabase | |||
36 | 36 | ||
37 | fn infer(def_id: DefId) -> Cancelable<Arc<InferenceResult>> { | 37 | fn infer(def_id: DefId) -> Cancelable<Arc<InferenceResult>> { |
38 | type InferQuery; | 38 | type InferQuery; |
39 | use fn query_definitions::infer; | 39 | use fn crate::ty::infer; |
40 | } | 40 | } |
41 | 41 | ||
42 | fn type_for_def(def_id: DefId) -> Cancelable<Ty> { | 42 | fn type_for_def(def_id: DefId) -> Cancelable<Ty> { |
43 | type TypeForDefQuery; | 43 | type TypeForDefQuery; |
44 | use fn query_definitions::type_for_def; | 44 | use fn crate::ty::type_for_def; |
45 | } | 45 | } |
46 | 46 | ||
47 | fn type_for_field(def_id: DefId, field: Name) -> Cancelable<Ty> { | 47 | fn type_for_field(def_id: DefId, field: Name) -> Cancelable<Ty> { |
48 | type TypeForFieldQuery; | 48 | type TypeForFieldQuery; |
49 | use fn query_definitions::type_for_field; | 49 | use fn crate::ty::type_for_field; |
50 | } | 50 | } |
51 | 51 | ||
52 | fn file_items(file_id: FileId) -> Arc<SourceFileItems> { | 52 | fn file_items(file_id: FileId) -> Arc<SourceFileItems> { |
diff --git a/crates/ra_hir/src/query_definitions.rs b/crates/ra_hir/src/query_definitions.rs index 016d86ee6..721bd4195 100644 --- a/crates/ra_hir/src/query_definitions.rs +++ b/crates/ra_hir/src/query_definitions.rs | |||
@@ -19,7 +19,6 @@ use crate::{ | |||
19 | imp::Submodule, | 19 | imp::Submodule, |
20 | nameres::{InputModuleItems, ItemMap, Resolver}, | 20 | nameres::{InputModuleItems, ItemMap, Resolver}, |
21 | }, | 21 | }, |
22 | ty::{self, InferenceResult, Ty}, | ||
23 | adt::{StructData, EnumData}, | 22 | adt::{StructData, EnumData}, |
24 | }; | 23 | }; |
25 | 24 | ||
@@ -30,19 +29,6 @@ pub(super) fn fn_scopes(db: &impl HirDatabase, def_id: DefId) -> Arc<FnScopes> { | |||
30 | Arc::new(res) | 29 | Arc::new(res) |
31 | } | 30 | } |
32 | 31 | ||
33 | pub(super) fn infer(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Arc<InferenceResult>> { | ||
34 | let function = Function::new(def_id); | ||
35 | ty::infer(db, function).map(Arc::new) | ||
36 | } | ||
37 | |||
38 | pub(super) fn type_for_def(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Ty> { | ||
39 | ty::type_for_def(db, def_id) | ||
40 | } | ||
41 | |||
42 | pub(super) fn type_for_field(db: &impl HirDatabase, def_id: DefId, field: Name) -> Cancelable<Ty> { | ||
43 | ty::type_for_field(db, def_id, field) | ||
44 | } | ||
45 | |||
46 | pub(super) fn struct_data(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Arc<StructData>> { | 32 | pub(super) fn struct_data(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Arc<StructData>> { |
47 | let def_loc = def_id.loc(db); | 33 | let def_loc = def_id.loc(db); |
48 | assert!(def_loc.kind == DefKind::Struct); | 34 | assert!(def_loc.kind == DefKind::Struct); |
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs index 4ebd44d27..719b3f7cd 100644 --- a/crates/ra_hir/src/ty.rs +++ b/crates/ra_hir/src/ty.rs | |||
@@ -1,3 +1,18 @@ | |||
1 | //! The type system. We currently use this to infer types for completion. | ||
2 | //! | ||
3 | //! For type inference, compare the implementations in rustc (the various | ||
4 | //! check_* methods in librustc_typeck/check/mod.rs are a good entry point) and | ||
5 | //! IntelliJ-Rust (org.rust.lang.core.types.infer). Our entry point for | ||
6 | //! inference here is the `infer` function, which infers the types of all | ||
7 | //! expressions in a given function. | ||
8 | //! | ||
9 | //! The central struct here is `Ty`, which represents a type. During inference, | ||
10 | //! it can contain type 'variables' which represent currently unknown types; as | ||
11 | //! we walk through the expressions, we might determine that certain variables | ||
12 | //! need to be equal to each other, or to certain types. To record this, we use | ||
13 | //! the union-find implementation from the `ena` crate, which is extracted from | ||
14 | //! rustc. | ||
15 | |||
1 | mod primitive; | 16 | mod primitive; |
2 | #[cfg(test)] | 17 | #[cfg(test)] |
3 | mod tests; | 18 | mod tests; |
@@ -21,6 +36,7 @@ use crate::{ | |||
21 | type_ref::{TypeRef, Mutability}, | 36 | type_ref::{TypeRef, Mutability}, |
22 | }; | 37 | }; |
23 | 38 | ||
39 | /// The ID of a type variable. | ||
24 | #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)] | 40 | #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)] |
25 | pub struct TypeVarId(u32); | 41 | pub struct TypeVarId(u32); |
26 | 42 | ||
@@ -40,6 +56,8 @@ impl UnifyKey for TypeVarId { | |||
40 | } | 56 | } |
41 | } | 57 | } |
42 | 58 | ||
59 | /// The value of a type variable: either we already know the type, or we don't | ||
60 | /// know it yet. | ||
43 | #[derive(Clone, PartialEq, Eq, Debug)] | 61 | #[derive(Clone, PartialEq, Eq, Debug)] |
44 | pub enum TypeVarValue { | 62 | pub enum TypeVarValue { |
45 | Known(Ty), | 63 | Known(Ty), |
@@ -47,7 +65,7 @@ pub enum TypeVarValue { | |||
47 | } | 65 | } |
48 | 66 | ||
49 | impl TypeVarValue { | 67 | impl TypeVarValue { |
50 | pub fn known(&self) -> Option<&Ty> { | 68 | fn known(&self) -> Option<&Ty> { |
51 | match self { | 69 | match self { |
52 | TypeVarValue::Known(ty) => Some(ty), | 70 | TypeVarValue::Known(ty) => Some(ty), |
53 | TypeVarValue::Unknown => None, | 71 | TypeVarValue::Unknown => None, |
@@ -75,10 +93,13 @@ impl UnifyValue for TypeVarValue { | |||
75 | } | 93 | } |
76 | } | 94 | } |
77 | 95 | ||
96 | /// The kinds of placeholders we need during type inference. Currently, we only | ||
97 | /// have type variables; in the future, we will probably also need int and float | ||
98 | /// variables, for inference of literal values (e.g. `100` could be one of | ||
99 | /// several integer types). | ||
78 | #[derive(Clone, PartialEq, Eq, Hash, Debug)] | 100 | #[derive(Clone, PartialEq, Eq, Hash, Debug)] |
79 | pub enum InferTy { | 101 | pub enum InferTy { |
80 | TypeVar(TypeVarId), | 102 | TypeVar(TypeVarId), |
81 | // later we'll have IntVar and FloatVar as well | ||
82 | } | 103 | } |
83 | 104 | ||
84 | /// When inferring an expression, we propagate downward whatever type hint we | 105 | /// When inferring an expression, we propagate downward whatever type hint we |
@@ -92,15 +113,21 @@ struct Expectation { | |||
92 | } | 113 | } |
93 | 114 | ||
94 | impl Expectation { | 115 | impl Expectation { |
116 | /// The expectation that the type of the expression needs to equal the given | ||
117 | /// type. | ||
95 | fn has_type(ty: Ty) -> Self { | 118 | fn has_type(ty: Ty) -> Self { |
96 | Expectation { ty } | 119 | Expectation { ty } |
97 | } | 120 | } |
98 | 121 | ||
122 | /// This expresses no expectation on the type. | ||
99 | fn none() -> Self { | 123 | fn none() -> Self { |
100 | Expectation { ty: Ty::Unknown } | 124 | Expectation { ty: Ty::Unknown } |
101 | } | 125 | } |
102 | } | 126 | } |
103 | 127 | ||
128 | /// A type. This is based on the `TyKind` enum in rustc (librustc/ty/sty.rs). | ||
129 | /// | ||
130 | /// This should be cheap to clone. | ||
104 | #[derive(Clone, PartialEq, Eq, Hash, Debug)] | 131 | #[derive(Clone, PartialEq, Eq, Hash, Debug)] |
105 | pub enum Ty { | 132 | pub enum Ty { |
106 | /// The primitive boolean type. Written as `bool`. | 133 | /// The primitive boolean type. Written as `bool`. |
@@ -134,14 +161,14 @@ pub enum Ty { | |||
134 | // An array with the given length. Written as `[T; n]`. | 161 | // An array with the given length. Written as `[T; n]`. |
135 | // Array(Ty, ty::Const), | 162 | // Array(Ty, ty::Const), |
136 | /// The pointee of an array slice. Written as `[T]`. | 163 | /// The pointee of an array slice. Written as `[T]`. |
137 | Slice(TyRef), | 164 | Slice(Arc<Ty>), |
138 | 165 | ||
139 | /// A raw pointer. Written as `*mut T` or `*const T` | 166 | /// A raw pointer. Written as `*mut T` or `*const T` |
140 | RawPtr(TyRef, Mutability), | 167 | RawPtr(Arc<Ty>, Mutability), |
141 | 168 | ||
142 | /// A reference; a pointer with an associated lifetime. Written as | 169 | /// A reference; a pointer with an associated lifetime. Written as |
143 | /// `&'a mut T` or `&'a T`. | 170 | /// `&'a mut T` or `&'a T`. |
144 | Ref(TyRef, Mutability), | 171 | Ref(Arc<Ty>, Mutability), |
145 | 172 | ||
146 | /// A pointer to a function. Written as `fn() -> i32`. | 173 | /// A pointer to a function. Written as `fn() -> i32`. |
147 | /// | 174 | /// |
@@ -153,6 +180,10 @@ pub enum Ty { | |||
153 | /// ``` | 180 | /// ``` |
154 | FnPtr(Arc<FnSig>), | 181 | FnPtr(Arc<FnSig>), |
155 | 182 | ||
183 | // rustc has a separate type for each function, which just coerces to the | ||
184 | // above function pointer type. Once we implement generics, we will probably | ||
185 | // need this as well. | ||
186 | |||
156 | // A trait, defined with `dyn trait`. | 187 | // A trait, defined with `dyn trait`. |
157 | // Dynamic(), | 188 | // Dynamic(), |
158 | // The anonymous type of a closure. Used to represent the type of | 189 | // The anonymous type of a closure. Used to represent the type of |
@@ -166,7 +197,7 @@ pub enum Ty { | |||
166 | // A type representin the types stored inside a generator. | 197 | // A type representin the types stored inside a generator. |
167 | // This should only appear in GeneratorInteriors. | 198 | // This should only appear in GeneratorInteriors. |
168 | // GeneratorWitness(Binder<&'tcx List<Ty<'tcx>>>), | 199 | // GeneratorWitness(Binder<&'tcx List<Ty<'tcx>>>), |
169 | /// The never type `!` | 200 | /// The never type `!`. |
170 | Never, | 201 | Never, |
171 | 202 | ||
172 | /// A tuple type. For example, `(i32, bool)`. | 203 | /// A tuple type. For example, `(i32, bool)`. |
@@ -177,10 +208,6 @@ pub enum Ty { | |||
177 | // Projection(ProjectionTy), | 208 | // Projection(ProjectionTy), |
178 | 209 | ||
179 | // Opaque (`impl Trait`) type found in a return type. | 210 | // Opaque (`impl Trait`) type found in a return type. |
180 | // The `DefId` comes either from | ||
181 | // * the `impl Trait` ast::Ty node, | ||
182 | // * or the `existential type` declaration | ||
183 | // The substitutions are for the generics of the function in question. | ||
184 | // Opaque(DefId, Substs), | 211 | // Opaque(DefId, Substs), |
185 | 212 | ||
186 | // A type parameter; for example, `T` in `fn f<T>(x: T) {} | 213 | // A type parameter; for example, `T` in `fn f<T>(x: T) {} |
@@ -192,12 +219,12 @@ pub enum Ty { | |||
192 | /// A placeholder for a type which could not be computed; this is propagated | 219 | /// A placeholder for a type which could not be computed; this is propagated |
193 | /// to avoid useless error messages. Doubles as a placeholder where type | 220 | /// to avoid useless error messages. Doubles as a placeholder where type |
194 | /// variables are inserted before type checking, since we want to try to | 221 | /// variables are inserted before type checking, since we want to try to |
195 | /// infer a better type here anyway. | 222 | /// infer a better type here anyway -- for the IDE use case, we want to try |
223 | /// to infer as much as possible even in the presence of type errors. | ||
196 | Unknown, | 224 | Unknown, |
197 | } | 225 | } |
198 | 226 | ||
199 | type TyRef = Arc<Ty>; | 227 | /// A function signature. |
200 | |||
201 | #[derive(Clone, PartialEq, Eq, Hash, Debug)] | 228 | #[derive(Clone, PartialEq, Eq, Hash, Debug)] |
202 | pub struct FnSig { | 229 | pub struct FnSig { |
203 | input: Vec<Ty>, | 230 | input: Vec<Ty>, |
@@ -368,7 +395,11 @@ impl fmt::Display for Ty { | |||
368 | } | 395 | } |
369 | } | 396 | } |
370 | 397 | ||
371 | pub fn type_for_fn(db: &impl HirDatabase, f: Function) -> Cancelable<Ty> { | 398 | // Functions returning declared types for items |
399 | |||
400 | /// Compute the declared type of a function. This should not need to look at the | ||
401 | /// function body (but currently uses the function AST, so does anyway - TODO). | ||
402 | fn type_for_fn(db: &impl HirDatabase, f: Function) -> Cancelable<Ty> { | ||
372 | let syntax = f.syntax(db); | 403 | let syntax = f.syntax(db); |
373 | let module = f.module(db)?; | 404 | let module = f.module(db)?; |
374 | let node = syntax.borrowed(); | 405 | let node = syntax.borrowed(); |
@@ -390,7 +421,7 @@ pub fn type_for_fn(db: &impl HirDatabase, f: Function) -> Cancelable<Ty> { | |||
390 | Ok(Ty::FnPtr(Arc::new(sig))) | 421 | Ok(Ty::FnPtr(Arc::new(sig))) |
391 | } | 422 | } |
392 | 423 | ||
393 | pub fn type_for_struct(db: &impl HirDatabase, s: Struct) -> Cancelable<Ty> { | 424 | fn type_for_struct(db: &impl HirDatabase, s: Struct) -> Cancelable<Ty> { |
394 | Ok(Ty::Adt { | 425 | Ok(Ty::Adt { |
395 | def_id: s.def_id(), | 426 | def_id: s.def_id(), |
396 | name: s.name(db)?.unwrap_or_else(Name::missing), | 427 | name: s.name(db)?.unwrap_or_else(Name::missing), |
@@ -404,7 +435,7 @@ pub fn type_for_enum(db: &impl HirDatabase, s: Enum) -> Cancelable<Ty> { | |||
404 | }) | 435 | }) |
405 | } | 436 | } |
406 | 437 | ||
407 | pub fn type_for_def(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Ty> { | 438 | pub(super) fn type_for_def(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Ty> { |
408 | let def = def_id.resolve(db)?; | 439 | let def = def_id.resolve(db)?; |
409 | match def { | 440 | match def { |
410 | Def::Module(..) => { | 441 | Def::Module(..) => { |
@@ -444,19 +475,25 @@ pub(super) fn type_for_field(db: &impl HirDatabase, def_id: DefId, field: Name) | |||
444 | Ty::from_hir(db, &module, &type_ref) | 475 | Ty::from_hir(db, &module, &type_ref) |
445 | } | 476 | } |
446 | 477 | ||
478 | /// The result of type inference: A mapping from expressions and patterns to types. | ||
447 | #[derive(Clone, PartialEq, Eq, Debug)] | 479 | #[derive(Clone, PartialEq, Eq, Debug)] |
448 | pub struct InferenceResult { | 480 | pub struct InferenceResult { |
449 | type_of: FxHashMap<LocalSyntaxPtr, Ty>, | 481 | type_of: FxHashMap<LocalSyntaxPtr, Ty>, |
450 | } | 482 | } |
451 | 483 | ||
452 | impl InferenceResult { | 484 | impl InferenceResult { |
485 | /// Returns the type of the given syntax node, if it was inferred. Will | ||
486 | /// return `None` for syntax nodes not in the inferred function or not | ||
487 | /// pointing to an expression/pattern, `Some(Ty::Unknown)` for | ||
488 | /// expressions/patterns that could not be inferred. | ||
453 | pub fn type_of_node(&self, node: SyntaxNodeRef) -> Option<Ty> { | 489 | pub fn type_of_node(&self, node: SyntaxNodeRef) -> Option<Ty> { |
454 | self.type_of.get(&LocalSyntaxPtr::new(node)).cloned() | 490 | self.type_of.get(&LocalSyntaxPtr::new(node)).cloned() |
455 | } | 491 | } |
456 | } | 492 | } |
457 | 493 | ||
494 | /// The inference context contains all information needed during type inference. | ||
458 | #[derive(Clone, Debug)] | 495 | #[derive(Clone, Debug)] |
459 | pub struct InferenceContext<'a, D: HirDatabase> { | 496 | struct InferenceContext<'a, D: HirDatabase> { |
460 | db: &'a D, | 497 | db: &'a D, |
461 | scopes: Arc<FnScopes>, | 498 | scopes: Arc<FnScopes>, |
462 | module: Module, | 499 | module: Module, |
@@ -738,6 +775,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> { | |||
738 | ast::Expr::ParenExpr(e) => self.infer_expr_opt(e.expr(), expected)?, | 775 | ast::Expr::ParenExpr(e) => self.infer_expr_opt(e.expr(), expected)?, |
739 | ast::Expr::Label(_e) => Ty::Unknown, | 776 | ast::Expr::Label(_e) => Ty::Unknown, |
740 | ast::Expr::ReturnExpr(e) => { | 777 | ast::Expr::ReturnExpr(e) => { |
778 | // TODO expect return type of function | ||
741 | self.infer_expr_opt(e.expr(), &Expectation::none())?; | 779 | self.infer_expr_opt(e.expr(), &Expectation::none())?; |
742 | Ty::Never | 780 | Ty::Never |
743 | } | 781 | } |
@@ -870,7 +908,8 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> { | |||
870 | } | 908 | } |
871 | } | 909 | } |
872 | 910 | ||
873 | pub fn infer(db: &impl HirDatabase, function: Function) -> Cancelable<InferenceResult> { | 911 | pub fn infer(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Arc<InferenceResult>> { |
912 | let function = Function::new(def_id); // TODO: consts also need inference | ||
874 | let scopes = function.scopes(db); | 913 | let scopes = function.scopes(db); |
875 | let module = function.module(db)?; | 914 | let module = function.module(db)?; |
876 | let mut ctx = InferenceContext::new(db, scopes, module); | 915 | let mut ctx = InferenceContext::new(db, scopes, module); |
@@ -909,5 +948,5 @@ pub fn infer(db: &impl HirDatabase, function: Function) -> Cancelable<InferenceR | |||
909 | ctx.infer_block(block, &Expectation::has_type(ret_ty))?; | 948 | ctx.infer_block(block, &Expectation::has_type(ret_ty))?; |
910 | } | 949 | } |
911 | 950 | ||
912 | Ok(ctx.resolve_all()) | 951 | Ok(Arc::new(ctx.resolve_all())) |
913 | } | 952 | } |