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-rw-r--r--crates/hir_ty/src/infer.rs19
-rw-r--r--crates/hir_ty/src/infer/unify.rs36
-rw-r--r--crates/hir_ty/src/lib.rs2
-rw-r--r--crates/hir_ty/src/traits/chalk/mapping.rs106
-rw-r--r--crates/hir_ty/src/types.rs25
5 files changed, 85 insertions, 103 deletions
diff --git a/crates/hir_ty/src/infer.rs b/crates/hir_ty/src/infer.rs
index efe9198cc..75d633c96 100644
--- a/crates/hir_ty/src/infer.rs
+++ b/crates/hir_ty/src/infer.rs
@@ -683,25 +683,6 @@ impl<'a> InferenceContext<'a> {
683 } 683 }
684} 684}
685 685
686/// The kinds of placeholders we need during type inference. There's separate
687/// values for general types, and for integer and float variables. The latter
688/// two are used for inference of literal values (e.g. `100` could be one of
689/// several integer types).
690#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
691pub struct InferenceVar {
692 index: u32,
693}
694
695impl InferenceVar {
696 fn to_inner(self) -> unify::TypeVarId {
697 unify::TypeVarId(self.index)
698 }
699
700 fn from_inner(unify::TypeVarId(index): unify::TypeVarId) -> Self {
701 InferenceVar { index }
702 }
703}
704
705/// When inferring an expression, we propagate downward whatever type hint we 686/// When inferring an expression, we propagate downward whatever type hint we
706/// are able in the form of an `Expectation`. 687/// are able in the form of an `Expectation`.
707#[derive(Clone, PartialEq, Eq, Debug)] 688#[derive(Clone, PartialEq, Eq, Debug)]
diff --git a/crates/hir_ty/src/infer/unify.rs b/crates/hir_ty/src/infer/unify.rs
index 7d76cda68..d717e3375 100644
--- a/crates/hir_ty/src/infer/unify.rs
+++ b/crates/hir_ty/src/infer/unify.rs
@@ -51,7 +51,7 @@ impl<'a, 'b> Canonicalizer<'a, 'b> {
51 t.fold_binders( 51 t.fold_binders(
52 &mut |ty, binders| match ty.kind(&Interner) { 52 &mut |ty, binders| match ty.kind(&Interner) {
53 &TyKind::InferenceVar(var, kind) => { 53 &TyKind::InferenceVar(var, kind) => {
54 let inner = var.to_inner(); 54 let inner = from_inference_var(var);
55 if self.var_stack.contains(&inner) { 55 if self.var_stack.contains(&inner) {
56 // recursive type 56 // recursive type
57 return self.ctx.table.type_variable_table.fallback_value(var, kind); 57 return self.ctx.table.type_variable_table.fallback_value(var, kind);
@@ -65,7 +65,7 @@ impl<'a, 'b> Canonicalizer<'a, 'b> {
65 result 65 result
66 } else { 66 } else {
67 let root = self.ctx.table.var_unification_table.find(inner); 67 let root = self.ctx.table.var_unification_table.find(inner);
68 let position = self.add(InferenceVar::from_inner(root), kind); 68 let position = self.add(to_inference_var(root), kind);
69 TyKind::BoundVar(BoundVar::new(binders, position)).intern(&Interner) 69 TyKind::BoundVar(BoundVar::new(binders, position)).intern(&Interner)
70 } 70 }
71 } 71 }
@@ -207,16 +207,16 @@ impl TypeVariableTable {
207 } 207 }
208 208
209 pub(super) fn set_diverging(&mut self, iv: InferenceVar, diverging: bool) { 209 pub(super) fn set_diverging(&mut self, iv: InferenceVar, diverging: bool) {
210 self.inner[iv.to_inner().0 as usize].diverging = diverging; 210 self.inner[from_inference_var(iv).0 as usize].diverging = diverging;
211 } 211 }
212 212
213 fn is_diverging(&mut self, iv: InferenceVar) -> bool { 213 fn is_diverging(&mut self, iv: InferenceVar) -> bool {
214 self.inner[iv.to_inner().0 as usize].diverging 214 self.inner[from_inference_var(iv).0 as usize].diverging
215 } 215 }
216 216
217 fn fallback_value(&self, iv: InferenceVar, kind: TyVariableKind) -> Ty { 217 fn fallback_value(&self, iv: InferenceVar, kind: TyVariableKind) -> Ty {
218 match kind { 218 match kind {
219 _ if self.inner[iv.to_inner().0 as usize].diverging => TyKind::Never, 219 _ if self.inner[from_inference_var(iv).0 as usize].diverging => TyKind::Never,
220 TyVariableKind::General => TyKind::Error, 220 TyVariableKind::General => TyKind::Error,
221 TyVariableKind::Integer => TyKind::Scalar(Scalar::Int(IntTy::I32)), 221 TyVariableKind::Integer => TyKind::Scalar(Scalar::Int(IntTy::I32)),
222 TyVariableKind::Float => TyKind::Scalar(Scalar::Float(FloatTy::F64)), 222 TyVariableKind::Float => TyKind::Scalar(Scalar::Float(FloatTy::F64)),
@@ -250,7 +250,7 @@ impl InferenceTable {
250 self.type_variable_table.push(TypeVariableData { diverging }); 250 self.type_variable_table.push(TypeVariableData { diverging });
251 let key = self.var_unification_table.new_key(TypeVarValue::Unknown); 251 let key = self.var_unification_table.new_key(TypeVarValue::Unknown);
252 assert_eq!(key.0 as usize, self.type_variable_table.inner.len() - 1); 252 assert_eq!(key.0 as usize, self.type_variable_table.inner.len() - 1);
253 TyKind::InferenceVar(InferenceVar::from_inner(key), kind).intern(&Interner) 253 TyKind::InferenceVar(to_inference_var(key), kind).intern(&Interner)
254 } 254 }
255 255
256 pub(crate) fn new_type_var(&mut self) -> Ty { 256 pub(crate) fn new_type_var(&mut self) -> Ty {
@@ -369,8 +369,12 @@ impl InferenceTable {
369 == self.type_variable_table.is_diverging(*tv2) => 369 == self.type_variable_table.is_diverging(*tv2) =>
370 { 370 {
371 // both type vars are unknown since we tried to resolve them 371 // both type vars are unknown since we tried to resolve them
372 if !self.var_unification_table.unioned(tv1.to_inner(), tv2.to_inner()) { 372 if !self
373 self.var_unification_table.union(tv1.to_inner(), tv2.to_inner()); 373 .var_unification_table
374 .unioned(from_inference_var(*tv1), from_inference_var(*tv2))
375 {
376 self.var_unification_table
377 .union(from_inference_var(*tv1), from_inference_var(*tv2));
374 self.revision += 1; 378 self.revision += 1;
375 } 379 }
376 true 380 true
@@ -407,7 +411,7 @@ impl InferenceTable {
407 ) => { 411 ) => {
408 // the type var is unknown since we tried to resolve it 412 // the type var is unknown since we tried to resolve it
409 self.var_unification_table.union_value( 413 self.var_unification_table.union_value(
410 tv.to_inner(), 414 from_inference_var(*tv),
411 TypeVarValue::Known(other.clone().intern(&Interner)), 415 TypeVarValue::Known(other.clone().intern(&Interner)),
412 ); 416 );
413 self.revision += 1; 417 self.revision += 1;
@@ -462,7 +466,7 @@ impl InferenceTable {
462 } 466 }
463 match ty.kind(&Interner) { 467 match ty.kind(&Interner) {
464 TyKind::InferenceVar(tv, _) => { 468 TyKind::InferenceVar(tv, _) => {
465 let inner = tv.to_inner(); 469 let inner = from_inference_var(*tv);
466 match self.var_unification_table.inlined_probe_value(inner).known() { 470 match self.var_unification_table.inlined_probe_value(inner).known() {
467 Some(known_ty) => { 471 Some(known_ty) => {
468 // The known_ty can't be a type var itself 472 // The known_ty can't be a type var itself
@@ -485,7 +489,7 @@ impl InferenceTable {
485 fn resolve_ty_as_possible_inner(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty { 489 fn resolve_ty_as_possible_inner(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
486 ty.fold(&mut |ty| match ty.kind(&Interner) { 490 ty.fold(&mut |ty| match ty.kind(&Interner) {
487 &TyKind::InferenceVar(tv, kind) => { 491 &TyKind::InferenceVar(tv, kind) => {
488 let inner = tv.to_inner(); 492 let inner = from_inference_var(tv);
489 if tv_stack.contains(&inner) { 493 if tv_stack.contains(&inner) {
490 cov_mark::hit!(type_var_cycles_resolve_as_possible); 494 cov_mark::hit!(type_var_cycles_resolve_as_possible);
491 // recursive type 495 // recursive type
@@ -512,7 +516,7 @@ impl InferenceTable {
512 fn resolve_ty_completely_inner(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty { 516 fn resolve_ty_completely_inner(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
513 ty.fold(&mut |ty| match ty.kind(&Interner) { 517 ty.fold(&mut |ty| match ty.kind(&Interner) {
514 &TyKind::InferenceVar(tv, kind) => { 518 &TyKind::InferenceVar(tv, kind) => {
515 let inner = tv.to_inner(); 519 let inner = from_inference_var(tv);
516 if tv_stack.contains(&inner) { 520 if tv_stack.contains(&inner) {
517 cov_mark::hit!(type_var_cycles_resolve_completely); 521 cov_mark::hit!(type_var_cycles_resolve_completely);
518 // recursive type 522 // recursive type
@@ -555,6 +559,14 @@ impl UnifyKey for TypeVarId {
555 } 559 }
556} 560}
557 561
562fn from_inference_var(var: InferenceVar) -> TypeVarId {
563 TypeVarId(var.index())
564}
565
566fn to_inference_var(TypeVarId(index): TypeVarId) -> InferenceVar {
567 index.into()
568}
569
558/// The value of a type variable: either we already know the type, or we don't 570/// The value of a type variable: either we already know the type, or we don't
559/// know it yet. 571/// know it yet.
560#[derive(Clone, PartialEq, Eq, Debug)] 572#[derive(Clone, PartialEq, Eq, Debug)]
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index f5b658cba..5c83a508d 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -42,7 +42,7 @@ use crate::{db::HirDatabase, display::HirDisplay, utils::generics};
42pub use autoderef::autoderef; 42pub use autoderef::autoderef;
43pub use builder::TyBuilder; 43pub use builder::TyBuilder;
44pub use chalk_ext::{ProjectionTyExt, TyExt}; 44pub use chalk_ext::{ProjectionTyExt, TyExt};
45pub use infer::{could_unify, InferenceResult, InferenceVar}; 45pub use infer::{could_unify, InferenceResult};
46pub use lower::{ 46pub use lower::{
47 associated_type_shorthand_candidates, callable_item_sig, CallableDefId, ImplTraitLoweringMode, 47 associated_type_shorthand_candidates, callable_item_sig, CallableDefId, ImplTraitLoweringMode,
48 TyDefId, TyLoweringContext, ValueTyDefId, 48 TyDefId, TyLoweringContext, ValueTyDefId,
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index cf73cb078..0536b934e 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -10,10 +10,9 @@ use base_db::salsa::InternKey;
10use hir_def::{GenericDefId, TypeAliasId}; 10use hir_def::{GenericDefId, TypeAliasId};
11 11
12use crate::{ 12use crate::{
13 chalk_ext::ProjectionTyExt, db::HirDatabase, dummy_usize_const, static_lifetime, AliasTy, 13 chalk_ext::ProjectionTyExt, db::HirDatabase, static_lifetime, AliasTy, CallableDefId,
14 CallableDefId, Canonical, Const, DomainGoal, FnPointer, GenericArg, InEnvironment, Lifetime, 14 Canonical, DomainGoal, FnPointer, GenericArg, InEnvironment, OpaqueTy, ProjectionTy,
15 OpaqueTy, ProjectionTy, QuantifiedWhereClause, Substitution, TraitRef, Ty, TypeWalk, 15 QuantifiedWhereClause, Substitution, TraitRef, Ty, TypeWalk, WhereClause,
16 WhereClause,
17}; 16};
18 17
19use super::interner::*; 18use super::interner::*;
@@ -23,16 +22,16 @@ impl ToChalk for Ty {
23 type Chalk = chalk_ir::Ty<Interner>; 22 type Chalk = chalk_ir::Ty<Interner>;
24 fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Ty<Interner> { 23 fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Ty<Interner> {
25 match self.into_inner() { 24 match self.into_inner() {
26 TyKind::Ref(m, lt, ty) => ref_to_chalk(db, m, lt, ty), 25 TyKind::Ref(m, lt, ty) => {
27 TyKind::Array(ty, size) => array_to_chalk(db, ty, size), 26 chalk_ir::TyKind::Ref(m, lt, ty.to_chalk(db)).intern(&Interner)
28 TyKind::Function(FnPointer { sig, substitution: substs, .. }) => { 27 }
28 TyKind::Array(ty, size) => {
29 chalk_ir::TyKind::Array(ty.to_chalk(db), size).intern(&Interner)
30 }
31 TyKind::Function(FnPointer { sig, substitution: substs, num_binders }) => {
29 let substitution = chalk_ir::FnSubst(substs.0.to_chalk(db)); 32 let substitution = chalk_ir::FnSubst(substs.0.to_chalk(db));
30 chalk_ir::TyKind::Function(chalk_ir::FnPointer { 33 chalk_ir::TyKind::Function(chalk_ir::FnPointer { num_binders, sig, substitution })
31 num_binders: 0, 34 .intern(&Interner)
32 sig,
33 substitution,
34 })
35 .intern(&Interner)
36 } 35 }
37 TyKind::AssociatedType(assoc_type_id, substs) => { 36 TyKind::AssociatedType(assoc_type_id, substs) => {
38 let substitution = substs.to_chalk(db); 37 let substitution = substs.to_chalk(db);
@@ -74,22 +73,13 @@ impl ToChalk for Ty {
74 chalk_ir::TyKind::Adt(adt_id, substitution).intern(&Interner) 73 chalk_ir::TyKind::Adt(adt_id, substitution).intern(&Interner)
75 } 74 }
76 TyKind::Alias(AliasTy::Projection(proj_ty)) => { 75 TyKind::Alias(AliasTy::Projection(proj_ty)) => {
77 let associated_ty_id = proj_ty.associated_ty_id; 76 chalk_ir::AliasTy::Projection(proj_ty.to_chalk(db))
78 let substitution = proj_ty.substitution.to_chalk(db);
79 chalk_ir::AliasTy::Projection(chalk_ir::ProjectionTy {
80 associated_ty_id,
81 substitution,
82 })
83 .cast(&Interner)
84 .intern(&Interner)
85 }
86 TyKind::Alias(AliasTy::Opaque(opaque_ty)) => {
87 let opaque_ty_id = opaque_ty.opaque_ty_id;
88 let substitution = opaque_ty.substitution.to_chalk(db);
89 chalk_ir::AliasTy::Opaque(chalk_ir::OpaqueTy { opaque_ty_id, substitution })
90 .cast(&Interner) 77 .cast(&Interner)
91 .intern(&Interner) 78 .intern(&Interner)
92 } 79 }
80 TyKind::Alias(AliasTy::Opaque(opaque_ty)) => {
81 chalk_ir::AliasTy::Opaque(opaque_ty.to_chalk(db)).cast(&Interner).intern(&Interner)
82 }
93 TyKind::Placeholder(idx) => idx.to_ty::<Interner>(&Interner), 83 TyKind::Placeholder(idx) => idx.to_ty::<Interner>(&Interner),
94 TyKind::BoundVar(idx) => chalk_ir::TyKind::BoundVar(idx).intern(&Interner), 84 TyKind::BoundVar(idx) => chalk_ir::TyKind::BoundVar(idx).intern(&Interner),
95 TyKind::InferenceVar(..) => panic!("uncanonicalized infer ty"), 85 TyKind::InferenceVar(..) => panic!("uncanonicalized infer ty"),
@@ -101,7 +91,7 @@ impl ToChalk for Ty {
101 ); 91 );
102 let bounded_ty = chalk_ir::DynTy { 92 let bounded_ty = chalk_ir::DynTy {
103 bounds: chalk_ir::Binders::new(binders, where_clauses), 93 bounds: chalk_ir::Binders::new(binders, where_clauses),
104 lifetime: static_lifetime(), 94 lifetime: dyn_ty.lifetime,
105 }; 95 };
106 chalk_ir::TyKind::Dyn(bounded_ty).intern(&Interner) 96 chalk_ir::TyKind::Dyn(bounded_ty).intern(&Interner)
107 } 97 }
@@ -114,17 +104,10 @@ impl ToChalk for Ty {
114 chalk_ir::TyKind::Array(ty, size) => TyKind::Array(from_chalk(db, ty), size), 104 chalk_ir::TyKind::Array(ty, size) => TyKind::Array(from_chalk(db, ty), size),
115 chalk_ir::TyKind::Placeholder(idx) => TyKind::Placeholder(idx), 105 chalk_ir::TyKind::Placeholder(idx) => TyKind::Placeholder(idx),
116 chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Projection(proj)) => { 106 chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Projection(proj)) => {
117 let associated_ty = proj.associated_ty_id; 107 TyKind::Alias(AliasTy::Projection(from_chalk(db, proj)))
118 let parameters = from_chalk(db, proj.substitution);
119 TyKind::Alias(AliasTy::Projection(ProjectionTy {
120 associated_ty_id: associated_ty,
121 substitution: parameters,
122 }))
123 } 108 }
124 chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Opaque(opaque_ty)) => { 109 chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Opaque(opaque_ty)) => {
125 let opaque_ty_id = opaque_ty.opaque_ty_id; 110 TyKind::Alias(AliasTy::Opaque(from_chalk(db, opaque_ty)))
126 let parameters = from_chalk(db, opaque_ty.substitution);
127 TyKind::Alias(AliasTy::Opaque(OpaqueTy { opaque_ty_id, substitution: parameters }))
128 } 111 }
129 chalk_ir::TyKind::Function(chalk_ir::FnPointer { 112 chalk_ir::TyKind::Function(chalk_ir::FnPointer {
130 num_binders, 113 num_binders,
@@ -138,18 +121,19 @@ impl ToChalk for Ty {
138 } 121 }
139 chalk_ir::TyKind::BoundVar(idx) => TyKind::BoundVar(idx), 122 chalk_ir::TyKind::BoundVar(idx) => TyKind::BoundVar(idx),
140 chalk_ir::TyKind::InferenceVar(_iv, _kind) => TyKind::Error, 123 chalk_ir::TyKind::InferenceVar(_iv, _kind) => TyKind::Error,
141 chalk_ir::TyKind::Dyn(where_clauses) => { 124 chalk_ir::TyKind::Dyn(dyn_ty) => {
142 assert_eq!(where_clauses.bounds.binders.len(&Interner), 1); 125 assert_eq!(dyn_ty.bounds.binders.len(&Interner), 1);
143 let bounds = where_clauses 126 let (bounds, binders) = dyn_ty.bounds.into_value_and_skipped_binders();
144 .bounds 127 let where_clauses = crate::QuantifiedWhereClauses::from_iter(
145 .skip_binders() 128 &Interner,
146 .iter(&Interner) 129 bounds.interned().iter().cloned().map(|p| from_chalk(db, p)),
147 .map(|c| from_chalk(db, c.clone())); 130 );
148 TyKind::Dyn(crate::DynTy { 131 TyKind::Dyn(crate::DynTy {
149 bounds: crate::Binders::new( 132 bounds: crate::Binders::new(binders, where_clauses),
150 where_clauses.bounds.binders.clone(), 133 // HACK: we sometimes get lifetime variables back in solutions
151 crate::QuantifiedWhereClauses::from_iter(&Interner, bounds), 134 // from Chalk, and don't have the infrastructure to substitute
152 ), 135 // them yet. So for now we just turn them into 'static right
136 // when we get them
153 lifetime: static_lifetime(), 137 lifetime: static_lifetime(),
154 }) 138 })
155 } 139 }
@@ -169,8 +153,12 @@ impl ToChalk for Ty {
169 } 153 }
170 chalk_ir::TyKind::Raw(mutability, ty) => TyKind::Raw(mutability, from_chalk(db, ty)), 154 chalk_ir::TyKind::Raw(mutability, ty) => TyKind::Raw(mutability, from_chalk(db, ty)),
171 chalk_ir::TyKind::Slice(ty) => TyKind::Slice(from_chalk(db, ty)), 155 chalk_ir::TyKind::Slice(ty) => TyKind::Slice(from_chalk(db, ty)),
172 chalk_ir::TyKind::Ref(mutability, lifetime, ty) => { 156 chalk_ir::TyKind::Ref(mutability, _lifetime, ty) => {
173 TyKind::Ref(mutability, lifetime, from_chalk(db, ty)) 157 // HACK: we sometimes get lifetime variables back in solutions
158 // from Chalk, and don't have the infrastructure to substitute
159 // them yet. So for now we just turn them into 'static right
160 // when we get them
161 TyKind::Ref(mutability, static_lifetime(), from_chalk(db, ty))
174 } 162 }
175 chalk_ir::TyKind::Str => TyKind::Str, 163 chalk_ir::TyKind::Str => TyKind::Str,
176 chalk_ir::TyKind::Never => TyKind::Never, 164 chalk_ir::TyKind::Never => TyKind::Never,
@@ -189,26 +177,6 @@ impl ToChalk for Ty {
189 } 177 }
190} 178}
191 179
192/// We currently don't model lifetimes, but Chalk does. So, we have to insert a
193/// fake lifetime here, because Chalks built-in logic may expect it to be there.
194fn ref_to_chalk(
195 db: &dyn HirDatabase,
196 mutability: chalk_ir::Mutability,
197 _lifetime: Lifetime,
198 ty: Ty,
199) -> chalk_ir::Ty<Interner> {
200 let arg = ty.to_chalk(db);
201 let lifetime = static_lifetime();
202 chalk_ir::TyKind::Ref(mutability, lifetime, arg).intern(&Interner)
203}
204
205/// We currently don't model constants, but Chalk does. So, we have to insert a
206/// fake constant here, because Chalks built-in logic may expect it to be there.
207fn array_to_chalk(db: &dyn HirDatabase, ty: Ty, _: Const) -> chalk_ir::Ty<Interner> {
208 let arg = ty.to_chalk(db);
209 chalk_ir::TyKind::Array(arg, dummy_usize_const()).intern(&Interner)
210}
211
212impl ToChalk for GenericArg { 180impl ToChalk for GenericArg {
213 type Chalk = chalk_ir::GenericArg<Interner>; 181 type Chalk = chalk_ir::GenericArg<Interner>;
214 182
diff --git a/crates/hir_ty/src/types.rs b/crates/hir_ty/src/types.rs
index 89c0ddd1a..eac1b7900 100644
--- a/crates/hir_ty/src/types.rs
+++ b/crates/hir_ty/src/types.rs
@@ -11,8 +11,7 @@ use smallvec::SmallVec;
11 11
12use crate::{ 12use crate::{
13 AssocTypeId, CanonicalVarKinds, ChalkTraitId, ClosureId, Const, FnDefId, FnSig, ForeignDefId, 13 AssocTypeId, CanonicalVarKinds, ChalkTraitId, ClosureId, Const, FnDefId, FnSig, ForeignDefId,
14 InferenceVar, Interner, Lifetime, OpaqueTyId, PlaceholderIndex, TypeWalk, VariableKind, 14 Interner, Lifetime, OpaqueTyId, PlaceholderIndex, TypeWalk, VariableKind, VariableKinds,
15 VariableKinds,
16}; 15};
17 16
18#[derive(Clone, PartialEq, Eq, Debug, Hash)] 17#[derive(Clone, PartialEq, Eq, Debug, Hash)]
@@ -524,3 +523,25 @@ pub enum Guidance {
524 /// There's no useful information to feed back to type inference 523 /// There's no useful information to feed back to type inference
525 Unknown, 524 Unknown,
526} 525}
526
527/// The kinds of placeholders we need during type inference. There's separate
528/// values for general types, and for integer and float variables. The latter
529/// two are used for inference of literal values (e.g. `100` could be one of
530/// several integer types).
531#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
532pub struct InferenceVar {
533 index: u32,
534}
535
536impl From<u32> for InferenceVar {
537 fn from(index: u32) -> InferenceVar {
538 InferenceVar { index }
539 }
540}
541
542impl InferenceVar {
543 /// Gets the underlying index value.
544 pub fn index(self) -> u32 {
545 self.index
546 }
547}