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)*) };
24 pub mod method_resolution;
36 fold::{Shift, TypeFoldable},
37 interner::HasInterner,
40 use hir_def::{expr::ExprId, type_ref::Rawness, TypeOrConstParamId};
41 use itertools::Either;
44 use crate::{consteval::unknown_const, db::HirDatabase, utils::generics};
46 pub use autoderef::autoderef;
47 pub use builder::{ParamKind, TyBuilder};
50 could_coerce, could_unify, Adjust, Adjustment, AutoBorrow, BindingMode, InferenceDiagnostic,
53 pub use interner::Interner;
55 associated_type_shorthand_candidates, callable_item_sig, CallableDefId, ImplTraitLoweringMode,
56 TyDefId, TyLoweringContext, ValueTyDefId,
59 from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id, from_placeholder_idx,
60 lt_from_placeholder_idx, to_assoc_type_id, to_chalk_trait_id, to_foreign_def_id,
63 pub use traits::TraitEnvironment;
64 pub use utils::{all_super_traits, is_fn_unsafe_to_call};
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 Environment = chalk_ir::Environment<Interner>;
116 pub type DomainGoal = chalk_ir::DomainGoal<Interner>;
117 pub type Goal = chalk_ir::Goal<Interner>;
118 pub type AliasEq = chalk_ir::AliasEq<Interner>;
119 pub type Solution = chalk_solve::Solution<Interner>;
120 pub type ConstrainedSubst = chalk_ir::ConstrainedSubst<Interner>;
121 pub type Guidance = chalk_solve::Guidance<Interner>;
122 pub type WhereClause = chalk_ir::WhereClause<Interner>;
124 // FIXME: get rid of this
125 pub fn subst_prefix(s: &Substitution, n: usize) -> Substitution {
126 Substitution::from_iter(
128 s.as_slice(Interner)[..std::cmp::min(s.len(Interner), n)].iter().cloned(),
132 /// Return an index of a parameter in the generic type parameter list by it's id.
133 pub fn param_idx(db: &dyn HirDatabase, id: TypeOrConstParamId) -> Option<usize> {
134 generics(db.upcast(), id.parent).param_idx(id)
137 pub(crate) fn wrap_empty_binders<T>(value: T) -> Binders<T>
139 T: TypeFoldable<Interner> + HasInterner<Interner = Interner>,
141 Binders::empty(Interner, value.shifted_in_from(Interner, DebruijnIndex::ONE))
144 pub(crate) fn make_type_and_const_binders<T: HasInterner<Interner = Interner>>(
145 which_is_const: impl Iterator<Item = Option<Ty>>,
149 VariableKinds::from_iter(
151 which_is_const.map(|x| {
152 if let Some(ty) = x {
153 chalk_ir::VariableKind::Const(ty)
155 chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General)
163 pub(crate) fn make_single_type_binders<T: HasInterner<Interner = Interner>>(
167 VariableKinds::from_iter(
169 std::iter::once(chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General)),
175 pub(crate) fn make_binders_with_count<T: HasInterner<Interner = Interner>>(
176 db: &dyn HirDatabase,
181 let it = generics.iter_id().take(count).map(|id| match id {
182 Either::Left(_) => None,
183 Either::Right(id) => Some(db.const_param_ty(id)),
185 crate::make_type_and_const_binders(it, value)
188 pub(crate) fn make_binders<T: HasInterner<Interner = Interner>>(
189 db: &dyn HirDatabase,
193 make_binders_with_count(db, usize::MAX, generics, value)
196 // FIXME: get rid of this
197 pub fn make_canonical<T: HasInterner<Interner = Interner>>(
199 kinds: impl IntoIterator<Item = TyVariableKind>,
201 let kinds = kinds.into_iter().map(|tk| {
202 chalk_ir::CanonicalVarKind::new(
203 chalk_ir::VariableKind::Ty(tk),
204 chalk_ir::UniverseIndex::ROOT,
207 Canonical { value, binders: chalk_ir::CanonicalVarKinds::from_iter(Interner, kinds) }
210 // FIXME: get rid of this, just replace it by FnPointer
211 /// A function signature as seen by type inference: Several parameter types and
213 #[derive(Clone, PartialEq, Eq, Debug)]
214 pub struct CallableSig {
215 params_and_return: Arc<[Ty]>,
219 has_interner!(CallableSig);
221 /// A polymorphic function signature.
222 pub type PolyFnSig = Binders<CallableSig>;
225 pub fn from_params_and_return(mut params: Vec<Ty>, ret: Ty, is_varargs: bool) -> CallableSig {
227 CallableSig { params_and_return: params.into(), is_varargs }
230 pub fn from_fn_ptr(fn_ptr: &FnPointer) -> CallableSig {
232 // FIXME: what to do about lifetime params? -> return PolyFnSig
233 params_and_return: fn_ptr
236 .shifted_out_to(Interner, DebruijnIndex::ONE)
237 .expect("unexpected lifetime vars in fn ptr")
241 .map(|arg| arg.assert_ty_ref(Interner).clone())
243 is_varargs: fn_ptr.sig.variadic,
247 pub fn to_fn_ptr(&self) -> FnPointer {
250 sig: FnSig { abi: (), safety: Safety::Safe, variadic: self.is_varargs },
251 substitution: FnSubst(Substitution::from_iter(
253 self.params_and_return.iter().cloned(),
258 pub fn params(&self) -> &[Ty] {
259 &self.params_and_return[0..self.params_and_return.len() - 1]
262 pub fn ret(&self) -> &Ty {
263 &self.params_and_return[self.params_and_return.len() - 1]
267 impl TypeFoldable<Interner> for CallableSig {
270 folder: &mut dyn chalk_ir::fold::TypeFolder<Interner, Error = E>,
271 outer_binder: DebruijnIndex,
272 ) -> Result<Self, E> {
273 let vec = self.params_and_return.to_vec();
274 let folded = vec.fold_with(folder, outer_binder)?;
275 Ok(CallableSig { params_and_return: folded.into(), is_varargs: self.is_varargs })
279 #[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
280 pub enum ImplTraitId {
281 ReturnTypeImplTrait(hir_def::FunctionId, u16),
282 AsyncBlockTypeImplTrait(hir_def::DefWithBodyId, ExprId),
285 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
286 pub struct ReturnTypeImplTraits {
287 pub(crate) impl_traits: Vec<ReturnTypeImplTrait>,
290 has_interner!(ReturnTypeImplTraits);
292 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
293 pub(crate) struct ReturnTypeImplTrait {
294 pub(crate) bounds: Binders<Vec<QuantifiedWhereClause>>,
297 pub fn static_lifetime() -> Lifetime {
298 LifetimeData::Static.intern(Interner)
301 pub(crate) fn fold_free_vars<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
303 for_ty: impl FnMut(BoundVar, DebruijnIndex) -> Ty,
304 for_const: impl FnMut(Ty, BoundVar, DebruijnIndex) -> Const,
306 use chalk_ir::{fold::TypeFolder, Fallible};
307 struct FreeVarFolder<F1, F2>(F1, F2);
310 F1: FnMut(BoundVar, DebruijnIndex) -> Ty + 'i,
311 F2: FnMut(Ty, BoundVar, DebruijnIndex) -> Const + 'i,
312 > TypeFolder<Interner> for FreeVarFolder<F1, F2>
314 type Error = NoSolution;
316 fn as_dyn(&mut self) -> &mut dyn TypeFolder<Interner, Error = Self::Error> {
320 fn interner(&self) -> Interner {
327 outer_binder: DebruijnIndex,
329 Ok(self.0(bound_var, outer_binder))
332 fn fold_free_var_const(
336 outer_binder: DebruijnIndex,
337 ) -> Fallible<Const> {
338 Ok(self.1(ty, bound_var, outer_binder))
341 t.fold_with(&mut FreeVarFolder(for_ty, for_const), DebruijnIndex::INNERMOST)
342 .expect("fold failed unexpectedly")
345 pub(crate) fn fold_tys<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
347 mut for_ty: impl FnMut(Ty, DebruijnIndex) -> Ty,
348 binders: DebruijnIndex,
353 Either::Left(x) => Either::Left(for_ty(x, d)),
354 Either::Right(x) => Either::Right(x),
360 pub(crate) fn fold_tys_and_consts<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
362 f: impl FnMut(Either<Ty, Const>, DebruijnIndex) -> Either<Ty, Const>,
363 binders: DebruijnIndex,
366 fold::{TypeFolder, TypeSuperFoldable},
369 struct TyFolder<F>(F);
370 impl<'i, F: FnMut(Either<Ty, Const>, DebruijnIndex) -> Either<Ty, Const> + 'i>
371 TypeFolder<Interner> for TyFolder<F>
373 type Error = NoSolution;
375 fn as_dyn(&mut self) -> &mut dyn TypeFolder<Interner, Error = Self::Error> {
379 fn interner(&self) -> Interner {
383 fn fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Fallible<Ty> {
384 let ty = ty.super_fold_with(self.as_dyn(), outer_binder)?;
385 Ok(self.0(Either::Left(ty), outer_binder).left().unwrap())
388 fn fold_const(&mut self, c: Const, outer_binder: DebruijnIndex) -> Fallible<Const> {
389 Ok(self.0(Either::Right(c), outer_binder).right().unwrap())
392 t.fold_with(&mut TyFolder(f), binders).expect("fold failed unexpectedly")
395 /// 'Canonicalizes' the `t` by replacing any errors with new variables. Also
396 /// ensures there are no unbound variables or inference variables anywhere in
398 pub fn replace_errors_with_variables<T>(t: &T) -> Canonical<T>
400 T: HasInterner<Interner = Interner> + TypeFoldable<Interner> + Clone,
401 T: HasInterner<Interner = Interner>,
404 fold::{TypeFolder, TypeSuperFoldable},
407 struct ErrorReplacer {
410 impl TypeFolder<Interner> for ErrorReplacer {
411 type Error = NoSolution;
413 fn as_dyn(&mut self) -> &mut dyn TypeFolder<Interner, Error = Self::Error> {
417 fn interner(&self) -> Interner {
421 fn fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Fallible<Ty> {
422 if let TyKind::Error = ty.kind(Interner) {
423 let index = self.vars;
425 Ok(TyKind::BoundVar(BoundVar::new(outer_binder, index)).intern(Interner))
427 let ty = ty.super_fold_with(self.as_dyn(), outer_binder)?;
432 fn fold_inference_ty(
435 _kind: TyVariableKind,
436 _outer_binder: DebruijnIndex,
438 if cfg!(debug_assertions) {
439 // we don't want to just panic here, because then the error message
440 // won't contain the whole thing, which would not be very helpful
443 Ok(TyKind::Error.intern(Interner))
449 _bound_var: BoundVar,
450 _outer_binder: DebruijnIndex,
452 if cfg!(debug_assertions) {
453 // we don't want to just panic here, because then the error message
454 // won't contain the whole thing, which would not be very helpful
457 Ok(TyKind::Error.intern(Interner))
461 fn fold_inference_const(
465 _outer_binder: DebruijnIndex,
466 ) -> Fallible<Const> {
467 if cfg!(debug_assertions) {
470 Ok(unknown_const(ty))
474 fn fold_free_var_const(
477 _bound_var: BoundVar,
478 _outer_binder: DebruijnIndex,
479 ) -> Fallible<Const> {
480 if cfg!(debug_assertions) {
483 Ok(unknown_const(ty))
487 fn fold_inference_lifetime(
490 _outer_binder: DebruijnIndex,
491 ) -> Fallible<Lifetime> {
492 if cfg!(debug_assertions) {
495 Ok(static_lifetime())
499 fn fold_free_var_lifetime(
501 _bound_var: BoundVar,
502 _outer_binder: DebruijnIndex,
503 ) -> Fallible<Lifetime> {
504 if cfg!(debug_assertions) {
507 Ok(static_lifetime())
511 let mut error_replacer = ErrorReplacer { vars: 0 };
512 let value = match t.clone().fold_with(&mut error_replacer, DebruijnIndex::INNERMOST) {
514 Err(_) => panic!("Encountered unbound or inference vars in {:?}", t),
516 let kinds = (0..error_replacer.vars).map(|_| {
517 chalk_ir::CanonicalVarKind::new(
518 chalk_ir::VariableKind::Ty(TyVariableKind::General),
519 chalk_ir::UniverseIndex::ROOT,
522 Canonical { value, binders: chalk_ir::CanonicalVarKinds::from_iter(Interner, kinds) }