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,
43 type_ref::{ConstScalar, Rawness},
47 use crate::{db::HirDatabase, display::HirDisplay, utils::generics};
49 pub use autoderef::autoderef;
50 pub use builder::TyBuilder;
52 pub use infer::{could_unify, InferenceResult};
53 pub use interner::Interner;
55 associated_type_shorthand_candidates, callable_item_sig, CallableDefId, ImplTraitLoweringMode,
56 TyDefId, TyLoweringContext, ValueTyDefId,
59 const_from_placeholder_idx, from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id,
60 from_placeholder_idx, lt_from_placeholder_idx, to_assoc_type_id, to_chalk_trait_id,
61 to_foreign_def_id, to_placeholder_idx,
63 pub use traits::TraitEnvironment;
64 pub use utils::all_super_traits;
65 pub use walk::TypeWalk;
68 cast::Cast, AdtId, BoundVar, DebruijnIndex, Mutability, Safety, Scalar, TyVariableKind,
71 pub type ForeignDefId = chalk_ir::ForeignDefId<Interner>;
72 pub type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
73 pub type FnDefId = chalk_ir::FnDefId<Interner>;
74 pub type ClosureId = chalk_ir::ClosureId<Interner>;
75 pub type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
76 pub type PlaceholderIndex = chalk_ir::PlaceholderIndex;
78 pub type VariableKind = chalk_ir::VariableKind<Interner>;
79 pub type VariableKinds = chalk_ir::VariableKinds<Interner>;
80 pub type CanonicalVarKinds = chalk_ir::CanonicalVarKinds<Interner>;
81 pub type Binders<T> = chalk_ir::Binders<T>;
82 pub type Substitution = chalk_ir::Substitution<Interner>;
83 pub type GenericArg = chalk_ir::GenericArg<Interner>;
84 pub type GenericArgData = chalk_ir::GenericArgData<Interner>;
86 pub type Ty = chalk_ir::Ty<Interner>;
87 pub type TyKind = chalk_ir::TyKind<Interner>;
88 pub type DynTy = chalk_ir::DynTy<Interner>;
89 pub type FnPointer = chalk_ir::FnPointer<Interner>;
90 // pub type FnSubst = chalk_ir::FnSubst<Interner>;
91 pub use chalk_ir::FnSubst;
92 pub type ProjectionTy = chalk_ir::ProjectionTy<Interner>;
93 pub type AliasTy = chalk_ir::AliasTy<Interner>;
94 pub type OpaqueTy = chalk_ir::OpaqueTy<Interner>;
95 pub type InferenceVar = chalk_ir::InferenceVar;
97 pub type Lifetime = chalk_ir::Lifetime<Interner>;
98 pub type LifetimeData = chalk_ir::LifetimeData<Interner>;
99 pub type LifetimeOutlives = chalk_ir::LifetimeOutlives<Interner>;
101 pub type Const = chalk_ir::Const<Interner>;
102 pub type ConstData = chalk_ir::ConstData<Interner>;
103 pub type ConstValue = chalk_ir::ConstValue<Interner>;
104 pub type ConcreteConst = chalk_ir::ConcreteConst<Interner>;
106 pub type ChalkTraitId = chalk_ir::TraitId<Interner>;
107 pub type TraitRef = chalk_ir::TraitRef<Interner>;
108 pub type QuantifiedWhereClause = Binders<WhereClause>;
109 pub type QuantifiedWhereClauses = chalk_ir::QuantifiedWhereClauses<Interner>;
110 pub type Canonical<T> = chalk_ir::Canonical<T>;
112 pub type FnSig = chalk_ir::FnSig<Interner>;
114 pub type InEnvironment<T> = chalk_ir::InEnvironment<T>;
115 pub type DomainGoal = chalk_ir::DomainGoal<Interner>;
116 pub type AliasEq = chalk_ir::AliasEq<Interner>;
117 pub type Solution = chalk_solve::Solution<Interner>;
118 pub type ConstrainedSubst = chalk_ir::ConstrainedSubst<Interner>;
119 pub type Guidance = chalk_solve::Guidance<Interner>;
120 pub type WhereClause = chalk_ir::WhereClause<Interner>;
122 // FIXME: get rid of this
123 pub fn subst_prefix(s: &Substitution, n: usize) -> Substitution {
124 Substitution::from_iter(
126 s.as_slice(&Interner)[..std::cmp::min(s.len(&Interner), n)].iter().cloned(),
130 /// Return an index of a parameter in the generic type parameter list by it's id.
131 pub fn param_idx(db: &dyn HirDatabase, id: TypeParamId) -> Option<usize> {
132 generics(db.upcast(), id.parent).param_idx(id)
135 pub(crate) fn wrap_empty_binders<T>(value: T) -> Binders<T>
137 T: Fold<Interner, Result = T> + HasInterner<Interner = Interner>,
139 Binders::empty(&Interner, value.shifted_in_from(&Interner, DebruijnIndex::ONE))
142 pub(crate) fn make_only_type_binders<T: HasInterner<Interner = Interner>>(
147 VariableKinds::from_iter(
149 std::iter::repeat(chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General))
156 // FIXME: get rid of this
157 pub fn make_canonical<T: HasInterner<Interner = Interner>>(
159 kinds: impl IntoIterator<Item = TyVariableKind>,
161 let kinds = kinds.into_iter().map(|tk| {
162 chalk_ir::CanonicalVarKind::new(
163 chalk_ir::VariableKind::Ty(tk),
164 chalk_ir::UniverseIndex::ROOT,
167 Canonical { value, binders: chalk_ir::CanonicalVarKinds::from_iter(&Interner, kinds) }
170 /// A function signature as seen by type inference: Several parameter types and
172 #[derive(Clone, PartialEq, Eq, Debug)]
173 pub struct CallableSig {
174 params_and_return: Arc<[Ty]>,
178 has_interner!(CallableSig);
180 /// A polymorphic function signature.
181 pub type PolyFnSig = Binders<CallableSig>;
184 pub fn from_params_and_return(mut params: Vec<Ty>, ret: Ty, is_varargs: bool) -> CallableSig {
186 CallableSig { params_and_return: params.into(), is_varargs }
189 pub fn from_fn_ptr(fn_ptr: &FnPointer) -> CallableSig {
191 // FIXME: what to do about lifetime params? -> return PolyFnSig
192 params_and_return: fn_ptr
195 .shifted_out_to(&Interner, DebruijnIndex::ONE)
196 .expect("unexpected lifetime vars in fn ptr")
200 .map(|arg| arg.assert_ty_ref(&Interner).clone())
202 is_varargs: fn_ptr.sig.variadic,
206 pub fn params(&self) -> &[Ty] {
207 &self.params_and_return[0..self.params_and_return.len() - 1]
210 pub fn ret(&self) -> &Ty {
211 &self.params_and_return[self.params_and_return.len() - 1]
215 impl Fold<Interner> for CallableSig {
216 type Result = CallableSig;
220 folder: &mut dyn chalk_ir::fold::Folder<'i, Interner>,
221 outer_binder: DebruijnIndex,
222 ) -> chalk_ir::Fallible<Self::Result>
226 let vec = self.params_and_return.to_vec();
227 let folded = vec.fold_with(folder, outer_binder)?;
228 Ok(CallableSig { params_and_return: folded.into(), is_varargs: self.is_varargs })
232 #[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
233 pub enum ImplTraitId {
234 ReturnTypeImplTrait(hir_def::FunctionId, u16),
235 AsyncBlockTypeImplTrait(hir_def::DefWithBodyId, ExprId),
238 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
239 pub struct ReturnTypeImplTraits {
240 pub(crate) impl_traits: Vec<ReturnTypeImplTrait>,
243 has_interner!(ReturnTypeImplTraits);
245 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
246 pub(crate) struct ReturnTypeImplTrait {
247 pub(crate) bounds: Binders<Vec<QuantifiedWhereClause>>,
250 pub fn static_lifetime() -> Lifetime {
251 LifetimeData::Static.intern(&Interner)
254 pub fn dummy_usize_const() -> Const {
255 let usize_ty = chalk_ir::TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner);
256 chalk_ir::ConstData {
258 value: chalk_ir::ConstValue::Concrete(chalk_ir::ConcreteConst {
259 interned: ConstScalar::Unknown,
265 pub(crate) fn fold_free_vars<T: HasInterner<Interner = Interner> + Fold<Interner>>(
267 f: impl FnMut(BoundVar, DebruijnIndex) -> Ty,
269 use chalk_ir::{fold::Folder, Fallible};
270 struct FreeVarFolder<F>(F);
271 impl<'i, F: FnMut(BoundVar, DebruijnIndex) -> Ty + 'i> Folder<'i, Interner> for FreeVarFolder<F> {
272 fn as_dyn(&mut self) -> &mut dyn Folder<'i, Interner> {
276 fn interner(&self) -> &'i Interner {
283 outer_binder: DebruijnIndex,
285 Ok(self.0(bound_var, outer_binder))
288 t.fold_with(&mut FreeVarFolder(f), DebruijnIndex::INNERMOST).expect("fold failed unexpectedly")
291 pub(crate) fn fold_tys<T: HasInterner<Interner = Interner> + Fold<Interner>>(
293 f: impl FnMut(Ty, DebruijnIndex) -> Ty,
294 binders: DebruijnIndex,
297 fold::{Folder, SuperFold},
300 struct TyFolder<F>(F);
301 impl<'i, F: FnMut(Ty, DebruijnIndex) -> Ty + 'i> Folder<'i, Interner> for TyFolder<F> {
302 fn as_dyn(&mut self) -> &mut dyn Folder<'i, Interner> {
306 fn interner(&self) -> &'i Interner {
310 fn fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Fallible<Ty> {
311 let ty = ty.super_fold_with(self.as_dyn(), outer_binder)?;
312 Ok(self.0(ty, outer_binder))
315 t.fold_with(&mut TyFolder(f), binders).expect("fold failed unexpectedly")