1 //! The type system. We currently use this to infer types for completion, hover
2 //! information and various assists.
5 macro_rules! eprintln {
6 ($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
25 pub mod method_resolution;
38 interner::HasInterner,
41 use hir_def::{expr::ExprId, type_ref::Rawness, TypeParamId};
43 use crate::{consts::ConstScalar, db::HirDatabase, display::HirDisplay, utils::generics};
45 pub use autoderef::autoderef;
46 pub use builder::TyBuilder;
48 pub use infer::{could_unify, InferenceResult};
49 pub use interner::Interner;
51 associated_type_shorthand_candidates, callable_item_sig, CallableDefId, ImplTraitLoweringMode,
52 TyDefId, TyLoweringContext, ValueTyDefId,
55 const_from_placeholder_idx, from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id,
56 from_placeholder_idx, lt_from_placeholder_idx, to_assoc_type_id, to_chalk_trait_id,
57 to_foreign_def_id, to_placeholder_idx,
59 pub use traits::TraitEnvironment;
60 pub use utils::all_super_traits;
61 pub use walk::TypeWalk;
64 cast::Cast, AdtId, BoundVar, DebruijnIndex, Mutability, Safety, Scalar, TyVariableKind,
67 pub type ForeignDefId = chalk_ir::ForeignDefId<Interner>;
68 pub type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
69 pub type FnDefId = chalk_ir::FnDefId<Interner>;
70 pub type ClosureId = chalk_ir::ClosureId<Interner>;
71 pub type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
72 pub type PlaceholderIndex = chalk_ir::PlaceholderIndex;
74 pub type VariableKind = chalk_ir::VariableKind<Interner>;
75 pub type VariableKinds = chalk_ir::VariableKinds<Interner>;
76 pub type CanonicalVarKinds = chalk_ir::CanonicalVarKinds<Interner>;
77 pub type Binders<T> = chalk_ir::Binders<T>;
78 pub type Substitution = chalk_ir::Substitution<Interner>;
79 pub type GenericArg = chalk_ir::GenericArg<Interner>;
80 pub type GenericArgData = chalk_ir::GenericArgData<Interner>;
82 pub type Ty = chalk_ir::Ty<Interner>;
83 pub type TyKind = chalk_ir::TyKind<Interner>;
84 pub type DynTy = chalk_ir::DynTy<Interner>;
85 pub type FnPointer = chalk_ir::FnPointer<Interner>;
86 // pub type FnSubst = chalk_ir::FnSubst<Interner>;
87 pub use chalk_ir::FnSubst;
88 pub type ProjectionTy = chalk_ir::ProjectionTy<Interner>;
89 pub type AliasTy = chalk_ir::AliasTy<Interner>;
90 pub type OpaqueTy = chalk_ir::OpaqueTy<Interner>;
91 pub type InferenceVar = chalk_ir::InferenceVar;
93 pub type Lifetime = chalk_ir::Lifetime<Interner>;
94 pub type LifetimeData = chalk_ir::LifetimeData<Interner>;
95 pub type LifetimeOutlives = chalk_ir::LifetimeOutlives<Interner>;
97 pub type Const = chalk_ir::Const<Interner>;
98 pub type ConstData = chalk_ir::ConstData<Interner>;
99 pub type ConstValue = chalk_ir::ConstValue<Interner>;
100 pub type ConcreteConst = chalk_ir::ConcreteConst<Interner>;
102 pub type ChalkTraitId = chalk_ir::TraitId<Interner>;
103 pub type TraitRef = chalk_ir::TraitRef<Interner>;
104 pub type QuantifiedWhereClause = Binders<WhereClause>;
105 pub type QuantifiedWhereClauses = chalk_ir::QuantifiedWhereClauses<Interner>;
106 pub type Canonical<T> = chalk_ir::Canonical<T>;
108 pub type FnSig = chalk_ir::FnSig<Interner>;
110 pub type InEnvironment<T> = chalk_ir::InEnvironment<T>;
111 pub type DomainGoal = chalk_ir::DomainGoal<Interner>;
112 pub type AliasEq = chalk_ir::AliasEq<Interner>;
113 pub type Solution = chalk_solve::Solution<Interner>;
114 pub type ConstrainedSubst = chalk_ir::ConstrainedSubst<Interner>;
115 pub type Guidance = chalk_solve::Guidance<Interner>;
116 pub type WhereClause = chalk_ir::WhereClause<Interner>;
118 // FIXME: get rid of this
119 pub fn subst_prefix(s: &Substitution, n: usize) -> Substitution {
120 Substitution::from_iter(
122 s.as_slice(&Interner)[..std::cmp::min(s.len(&Interner), n)].iter().cloned(),
126 /// Return an index of a parameter in the generic type parameter list by it's id.
127 pub fn param_idx(db: &dyn HirDatabase, id: TypeParamId) -> Option<usize> {
128 generics(db.upcast(), id.parent).param_idx(id)
131 pub(crate) fn wrap_empty_binders<T>(value: T) -> Binders<T>
133 T: Fold<Interner, Result = T> + HasInterner<Interner = Interner>,
135 Binders::empty(&Interner, value.shifted_in_from(&Interner, DebruijnIndex::ONE))
138 pub(crate) fn make_only_type_binders<T: HasInterner<Interner = Interner>>(
143 VariableKinds::from_iter(
145 std::iter::repeat(chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General))
152 // FIXME: get rid of this
153 pub fn make_canonical<T: HasInterner<Interner = Interner>>(
155 kinds: impl IntoIterator<Item = TyVariableKind>,
157 let kinds = kinds.into_iter().map(|tk| {
158 chalk_ir::CanonicalVarKind::new(
159 chalk_ir::VariableKind::Ty(tk),
160 chalk_ir::UniverseIndex::ROOT,
163 Canonical { value, binders: chalk_ir::CanonicalVarKinds::from_iter(&Interner, kinds) }
166 /// A function signature as seen by type inference: Several parameter types and
168 #[derive(Clone, PartialEq, Eq, Debug)]
169 pub struct CallableSig {
170 params_and_return: Arc<[Ty]>,
174 has_interner!(CallableSig);
176 /// A polymorphic function signature.
177 pub type PolyFnSig = Binders<CallableSig>;
180 pub fn from_params_and_return(mut params: Vec<Ty>, ret: Ty, is_varargs: bool) -> CallableSig {
182 CallableSig { params_and_return: params.into(), is_varargs }
185 pub fn from_fn_ptr(fn_ptr: &FnPointer) -> CallableSig {
187 // FIXME: what to do about lifetime params? -> return PolyFnSig
188 params_and_return: fn_ptr
191 .shifted_out_to(&Interner, DebruijnIndex::ONE)
192 .expect("unexpected lifetime vars in fn ptr")
196 .map(|arg| arg.assert_ty_ref(&Interner).clone())
198 is_varargs: fn_ptr.sig.variadic,
202 pub fn params(&self) -> &[Ty] {
203 &self.params_and_return[0..self.params_and_return.len() - 1]
206 pub fn ret(&self) -> &Ty {
207 &self.params_and_return[self.params_and_return.len() - 1]
211 impl Fold<Interner> for CallableSig {
212 type Result = CallableSig;
216 folder: &mut dyn chalk_ir::fold::Folder<'i, Interner>,
217 outer_binder: DebruijnIndex,
218 ) -> chalk_ir::Fallible<Self::Result>
222 let vec = self.params_and_return.to_vec();
223 let folded = vec.fold_with(folder, outer_binder)?;
224 Ok(CallableSig { params_and_return: folded.into(), is_varargs: self.is_varargs })
228 #[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
229 pub enum ImplTraitId {
230 ReturnTypeImplTrait(hir_def::FunctionId, u16),
231 AsyncBlockTypeImplTrait(hir_def::DefWithBodyId, ExprId),
234 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
235 pub struct ReturnTypeImplTraits {
236 pub(crate) impl_traits: Vec<ReturnTypeImplTrait>,
239 has_interner!(ReturnTypeImplTraits);
241 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
242 pub(crate) struct ReturnTypeImplTrait {
243 pub(crate) bounds: Binders<Vec<QuantifiedWhereClause>>,
246 pub fn static_lifetime() -> Lifetime {
247 LifetimeData::Static.intern(&Interner)
250 pub fn dummy_usize_const() -> Const {
251 let usize_ty = chalk_ir::TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner);
252 chalk_ir::ConstData {
254 value: chalk_ir::ConstValue::Concrete(chalk_ir::ConcreteConst {
255 interned: ConstScalar::Unknown,
261 pub(crate) fn fold_free_vars<T: HasInterner<Interner = Interner> + Fold<Interner>>(
263 f: impl FnMut(BoundVar, DebruijnIndex) -> Ty,
265 use chalk_ir::{fold::Folder, Fallible};
266 struct FreeVarFolder<F>(F);
267 impl<'i, F: FnMut(BoundVar, DebruijnIndex) -> Ty + 'i> Folder<'i, Interner> for FreeVarFolder<F> {
268 fn as_dyn(&mut self) -> &mut dyn Folder<'i, Interner> {
272 fn interner(&self) -> &'i Interner {
279 outer_binder: DebruijnIndex,
281 Ok(self.0(bound_var, outer_binder))
284 t.fold_with(&mut FreeVarFolder(f), DebruijnIndex::INNERMOST).expect("fold failed unexpectedly")
287 pub(crate) fn fold_tys<T: HasInterner<Interner = Interner> + Fold<Interner>>(
289 f: impl FnMut(Ty, DebruijnIndex) -> Ty,
290 binders: DebruijnIndex,
293 fold::{Folder, SuperFold},
296 struct TyFolder<F>(F);
297 impl<'i, F: FnMut(Ty, DebruijnIndex) -> Ty + 'i> Folder<'i, Interner> for TyFolder<F> {
298 fn as_dyn(&mut self) -> &mut dyn Folder<'i, Interner> {
302 fn interner(&self) -> &'i Interner {
306 fn fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Fallible<Ty> {
307 let ty = ty.super_fold_with(self.as_dyn(), outer_binder)?;
308 Ok(self.0(ty, outer_binder))
311 t.fold_with(&mut TyFolder(f), binders).expect("fold failed unexpectedly")