mirror of
https://github.com/rust-lang/rust.git
synced 2025-02-05 19:43:24 +00:00
Split up infer.rs further
- coercion logic goes to `coerce.rs` - expression inference goes to `expr.rs` - pattern inference goes to `pat.rs`
This commit is contained in:
Florian Diebold
parent
0896ca04c4
commit
2955fbc7e1
File diff suppressed because it is too large
Load Diff
336
crates/ra_hir/src/ty/infer/coerce.rs
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336
crates/ra_hir/src/ty/infer/coerce.rs
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@ -0,0 +1,336 @@
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//! Coercion logic. Coercions are certain type conversions that can implicitly
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//! happen in certain places, e.g. weakening `&mut` to `&` or deref coercions
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//! like going from `&Vec<T>` to `&[T]`.
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//!
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//! See: https://doc.rust-lang.org/nomicon/coercions.html
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use rustc_hash::FxHashMap;
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use test_utils::tested_by;
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use super::{InferTy, InferenceContext, TypeVarValue};
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use crate::{
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db::HirDatabase,
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lang_item::LangItemTarget,
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resolve::Resolver,
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ty::{autoderef, Substs, Ty, TypeCtor, TypeWalk},
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type_ref::Mutability,
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Adt,
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};
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impl<'a, D: HirDatabase> InferenceContext<'a, D> {
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/// Unify two types, but may coerce the first one to the second one
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/// using "implicit coercion rules" if needed.
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pub(super) fn coerce(&mut self, from_ty: &Ty, to_ty: &Ty) -> bool {
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let from_ty = self.resolve_ty_shallow(from_ty).into_owned();
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let to_ty = self.resolve_ty_shallow(to_ty);
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self.coerce_inner(from_ty, &to_ty)
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}
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/// Merge two types from different branches, with possible implicit coerce.
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///
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/// Note that it is only possible that one type are coerced to another.
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/// Coercing both types to another least upper bound type is not possible in rustc,
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/// which will simply result in "incompatible types" error.
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pub(super) fn coerce_merge_branch<'t>(&mut self, ty1: &Ty, ty2: &Ty) -> Ty {
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if self.coerce(ty1, ty2) {
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ty2.clone()
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} else if self.coerce(ty2, ty1) {
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ty1.clone()
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} else {
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tested_by!(coerce_merge_fail_fallback);
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// For incompatible types, we use the latter one as result
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// to be better recovery for `if` without `else`.
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ty2.clone()
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}
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}
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pub(super) fn init_coerce_unsized_map(
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db: &'a D,
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resolver: &Resolver,
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) -> FxHashMap<(TypeCtor, TypeCtor), usize> {
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let krate = resolver.krate().unwrap();
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let impls = match db.lang_item(krate, "coerce_unsized".into()) {
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Some(LangItemTarget::Trait(trait_)) => db.impls_for_trait(krate, trait_),
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_ => return FxHashMap::default(),
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};
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impls
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.iter()
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.filter_map(|impl_block| {
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// `CoerseUnsized` has one generic parameter for the target type.
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let trait_ref = impl_block.target_trait_ref(db)?;
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let cur_from_ty = trait_ref.substs.0.get(0)?;
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let cur_to_ty = trait_ref.substs.0.get(1)?;
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match (&cur_from_ty, cur_to_ty) {
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(ty_app!(ctor1, st1), ty_app!(ctor2, st2)) => {
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// FIXME: We return the first non-equal bound as the type parameter to coerce to unsized type.
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// This works for smart-pointer-like coercion, which covers all impls from std.
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st1.iter().zip(st2.iter()).enumerate().find_map(|(i, (ty1, ty2))| {
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match (ty1, ty2) {
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(Ty::Param { idx: p1, .. }, Ty::Param { idx: p2, .. })
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if p1 != p2 =>
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{
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Some(((*ctor1, *ctor2), i))
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}
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_ => None,
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}
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})
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}
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_ => None,
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}
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})
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.collect()
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}
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fn coerce_inner(&mut self, mut from_ty: Ty, to_ty: &Ty) -> bool {
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match (&from_ty, to_ty) {
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// Never type will make type variable to fallback to Never Type instead of Unknown.
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(ty_app!(TypeCtor::Never), Ty::Infer(InferTy::TypeVar(tv))) => {
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let var = self.new_maybe_never_type_var();
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self.var_unification_table.union_value(*tv, TypeVarValue::Known(var));
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return true;
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}
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(ty_app!(TypeCtor::Never), _) => return true,
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// Trivial cases, this should go after `never` check to
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// avoid infer result type to be never
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_ => {
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if self.unify_inner_trivial(&from_ty, &to_ty) {
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return true;
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}
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}
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}
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// Pointer weakening and function to pointer
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match (&mut from_ty, to_ty) {
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// `*mut T`, `&mut T, `&T`` -> `*const T`
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// `&mut T` -> `&T`
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// `&mut T` -> `*mut T`
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(ty_app!(c1@TypeCtor::RawPtr(_)), ty_app!(c2@TypeCtor::RawPtr(Mutability::Shared)))
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| (ty_app!(c1@TypeCtor::Ref(_)), ty_app!(c2@TypeCtor::RawPtr(Mutability::Shared)))
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| (ty_app!(c1@TypeCtor::Ref(_)), ty_app!(c2@TypeCtor::Ref(Mutability::Shared)))
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| (ty_app!(c1@TypeCtor::Ref(Mutability::Mut)), ty_app!(c2@TypeCtor::RawPtr(_))) => {
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*c1 = *c2;
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}
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// Illegal mutablity conversion
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(
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ty_app!(TypeCtor::RawPtr(Mutability::Shared)),
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ty_app!(TypeCtor::RawPtr(Mutability::Mut)),
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)
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| (
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ty_app!(TypeCtor::Ref(Mutability::Shared)),
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ty_app!(TypeCtor::Ref(Mutability::Mut)),
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) => return false,
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// `{function_type}` -> `fn()`
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(ty_app!(TypeCtor::FnDef(_)), ty_app!(TypeCtor::FnPtr { .. })) => {
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match from_ty.callable_sig(self.db) {
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None => return false,
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Some(sig) => {
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let num_args = sig.params_and_return.len() as u16 - 1;
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from_ty =
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Ty::apply(TypeCtor::FnPtr { num_args }, Substs(sig.params_and_return));
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}
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}
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}
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_ => {}
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}
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if let Some(ret) = self.try_coerce_unsized(&from_ty, &to_ty) {
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return ret;
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}
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// Auto Deref if cannot coerce
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match (&from_ty, to_ty) {
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// FIXME: DerefMut
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(ty_app!(TypeCtor::Ref(_), st1), ty_app!(TypeCtor::Ref(_), st2)) => {
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self.unify_autoderef_behind_ref(&st1[0], &st2[0])
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}
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// Otherwise, normal unify
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_ => self.unify(&from_ty, to_ty),
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}
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}
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/// Coerce a type using `from_ty: CoerceUnsized<ty_ty>`
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///
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/// See: https://doc.rust-lang.org/nightly/std/marker/trait.CoerceUnsized.html
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fn try_coerce_unsized(&mut self, from_ty: &Ty, to_ty: &Ty) -> Option<bool> {
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let (ctor1, st1, ctor2, st2) = match (from_ty, to_ty) {
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(ty_app!(ctor1, st1), ty_app!(ctor2, st2)) => (ctor1, st1, ctor2, st2),
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_ => return None,
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};
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let coerce_generic_index = *self.coerce_unsized_map.get(&(*ctor1, *ctor2))?;
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// Check `Unsize` first
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match self.check_unsize_and_coerce(
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st1.0.get(coerce_generic_index)?,
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st2.0.get(coerce_generic_index)?,
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0,
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) {
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Some(true) => {}
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ret => return ret,
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}
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let ret = st1
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.iter()
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.zip(st2.iter())
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.enumerate()
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.filter(|&(idx, _)| idx != coerce_generic_index)
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.all(|(_, (ty1, ty2))| self.unify(ty1, ty2));
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Some(ret)
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}
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/// Check if `from_ty: Unsize<to_ty>`, and coerce to `to_ty` if it holds.
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///
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/// It should not be directly called. It is only used by `try_coerce_unsized`.
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///
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/// See: https://doc.rust-lang.org/nightly/std/marker/trait.Unsize.html
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fn check_unsize_and_coerce(&mut self, from_ty: &Ty, to_ty: &Ty, depth: usize) -> Option<bool> {
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if depth > 1000 {
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panic!("Infinite recursion in coercion");
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}
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match (&from_ty, &to_ty) {
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// `[T; N]` -> `[T]`
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(ty_app!(TypeCtor::Array, st1), ty_app!(TypeCtor::Slice, st2)) => {
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Some(self.unify(&st1[0], &st2[0]))
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}
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// `T` -> `dyn Trait` when `T: Trait`
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(_, Ty::Dyn(_)) => {
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// FIXME: Check predicates
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Some(true)
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}
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// `(..., T)` -> `(..., U)` when `T: Unsize<U>`
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(
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ty_app!(TypeCtor::Tuple { cardinality: len1 }, st1),
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ty_app!(TypeCtor::Tuple { cardinality: len2 }, st2),
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) => {
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if len1 != len2 || *len1 == 0 {
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return None;
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}
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match self.check_unsize_and_coerce(
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st1.last().unwrap(),
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st2.last().unwrap(),
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depth + 1,
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) {
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Some(true) => {}
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ret => return ret,
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}
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let ret = st1[..st1.len() - 1]
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.iter()
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.zip(&st2[..st2.len() - 1])
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.all(|(ty1, ty2)| self.unify(ty1, ty2));
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Some(ret)
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}
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// Foo<..., T, ...> is Unsize<Foo<..., U, ...>> if:
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// - T: Unsize<U>
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// - Foo is a struct
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// - Only the last field of Foo has a type involving T
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// - T is not part of the type of any other fields
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// - Bar<T>: Unsize<Bar<U>>, if the last field of Foo has type Bar<T>
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(
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ty_app!(TypeCtor::Adt(Adt::Struct(struct1)), st1),
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ty_app!(TypeCtor::Adt(Adt::Struct(struct2)), st2),
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) if struct1 == struct2 => {
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let fields = struct1.fields(self.db);
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let (last_field, prev_fields) = fields.split_last()?;
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// Get the generic parameter involved in the last field.
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let unsize_generic_index = {
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let mut index = None;
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let mut multiple_param = false;
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last_field.ty(self.db).walk(&mut |ty| match ty {
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&Ty::Param { idx, .. } => {
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if index.is_none() {
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index = Some(idx);
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} else if Some(idx) != index {
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multiple_param = true;
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}
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}
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_ => {}
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});
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if multiple_param {
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return None;
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}
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index?
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};
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// Check other fields do not involve it.
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let mut multiple_used = false;
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prev_fields.iter().for_each(|field| {
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field.ty(self.db).walk(&mut |ty| match ty {
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&Ty::Param { idx, .. } if idx == unsize_generic_index => {
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multiple_used = true
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}
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_ => {}
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})
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});
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if multiple_used {
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return None;
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}
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let unsize_generic_index = unsize_generic_index as usize;
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// Check `Unsize` first
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match self.check_unsize_and_coerce(
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st1.get(unsize_generic_index)?,
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st2.get(unsize_generic_index)?,
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depth + 1,
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) {
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Some(true) => {}
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ret => return ret,
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}
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// Then unify other parameters
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let ret = st1
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.iter()
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.zip(st2.iter())
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.enumerate()
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.filter(|&(idx, _)| idx != unsize_generic_index)
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.all(|(_, (ty1, ty2))| self.unify(ty1, ty2));
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Some(ret)
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}
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_ => None,
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}
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}
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/// Unify `from_ty` to `to_ty` with optional auto Deref
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///
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/// Note that the parameters are already stripped the outer reference.
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fn unify_autoderef_behind_ref(&mut self, from_ty: &Ty, to_ty: &Ty) -> bool {
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let canonicalized = self.canonicalizer().canonicalize_ty(from_ty.clone());
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let to_ty = self.resolve_ty_shallow(&to_ty);
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// FIXME: Auto DerefMut
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for derefed_ty in
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autoderef::autoderef(self.db, &self.resolver.clone(), canonicalized.value.clone())
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{
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let derefed_ty = canonicalized.decanonicalize_ty(derefed_ty.value);
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match (&*self.resolve_ty_shallow(&derefed_ty), &*to_ty) {
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// Stop when constructor matches.
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(ty_app!(from_ctor, st1), ty_app!(to_ctor, st2)) if from_ctor == to_ctor => {
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// It will not recurse to `coerce`.
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return self.unify_substs(st1, st2, 0);
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}
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_ => {}
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}
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}
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false
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}
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}
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658
crates/ra_hir/src/ty/infer/expr.rs
Normal file
658
crates/ra_hir/src/ty/infer/expr.rs
Normal file
@ -0,0 +1,658 @@
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//! Type inference for expressions.
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use std::iter::{repeat, repeat_with};
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use std::sync::Arc;
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use super::{BindingMode, Expectation, InferenceContext, InferenceDiagnostic, TypeMismatch};
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use crate::{
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db::HirDatabase,
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expr::{self, Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp},
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generics::{GenericParams, HasGenericParams},
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name,
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nameres::Namespace,
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path::{GenericArg, GenericArgs},
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ty::{
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autoderef, method_resolution, op, primitive, CallableDef, InferTy, Mutability, Obligation,
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ProjectionPredicate, ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk,
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},
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Adt, Name,
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};
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impl<'a, D: HirDatabase> InferenceContext<'a, D> {
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pub(super) fn infer_expr(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
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let ty = self.infer_expr_inner(tgt_expr, expected);
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let could_unify = self.unify(&ty, &expected.ty);
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if !could_unify {
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self.result.type_mismatches.insert(
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tgt_expr,
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TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() },
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);
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}
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let ty = self.resolve_ty_as_possible(&mut vec![], ty);
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ty
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}
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/// Infer type of expression with possibly implicit coerce to the expected type.
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/// Return the type after possible coercion.
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fn infer_expr_coerce(&mut self, expr: ExprId, expected: &Expectation) -> Ty {
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let ty = self.infer_expr_inner(expr, &expected);
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let ty = if !self.coerce(&ty, &expected.ty) {
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self.result
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.type_mismatches
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.insert(expr, TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() });
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// Return actual type when type mismatch.
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// This is needed for diagnostic when return type mismatch.
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ty
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} else if expected.ty == Ty::Unknown {
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ty
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} else {
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expected.ty.clone()
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};
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self.resolve_ty_as_possible(&mut vec![], ty)
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}
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fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
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let body = Arc::clone(&self.body); // avoid borrow checker problem
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let ty = match &body[tgt_expr] {
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Expr::Missing => Ty::Unknown,
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Expr::If { condition, then_branch, else_branch } => {
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// if let is desugared to match, so this is always simple if
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self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
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let then_ty = self.infer_expr_inner(*then_branch, &expected);
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let else_ty = match else_branch {
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Some(else_branch) => self.infer_expr_inner(*else_branch, &expected),
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None => Ty::unit(),
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};
|
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|
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self.coerce_merge_branch(&then_ty, &else_ty)
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}
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Expr::Block { statements, tail } => self.infer_block(statements, *tail, expected),
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Expr::TryBlock { body } => {
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let _inner = self.infer_expr(*body, expected);
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// FIXME should be std::result::Result<{inner}, _>
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Ty::Unknown
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}
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Expr::Loop { body } => {
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self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
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// FIXME handle break with value
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Ty::simple(TypeCtor::Never)
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}
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Expr::While { condition, body } => {
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// while let is desugared to a match loop, so this is always simple while
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self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
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self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
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Ty::unit()
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}
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Expr::For { iterable, body, pat } => {
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let iterable_ty = self.infer_expr(*iterable, &Expectation::none());
|
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|
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let pat_ty = match self.resolve_into_iter_item() {
|
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Some(into_iter_item_alias) => {
|
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let pat_ty = self.new_type_var();
|
||||
let projection = ProjectionPredicate {
|
||||
ty: pat_ty.clone(),
|
||||
projection_ty: ProjectionTy {
|
||||
associated_ty: into_iter_item_alias,
|
||||
parameters: Substs::single(iterable_ty),
|
||||
},
|
||||
};
|
||||
self.obligations.push(Obligation::Projection(projection));
|
||||
self.resolve_ty_as_possible(&mut vec![], pat_ty)
|
||||
}
|
||||
None => Ty::Unknown,
|
||||
};
|
||||
|
||||
self.infer_pat(*pat, &pat_ty, BindingMode::default());
|
||||
self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
|
||||
Ty::unit()
|
||||
}
|
||||
Expr::Lambda { body, args, arg_types } => {
|
||||
assert_eq!(args.len(), arg_types.len());
|
||||
|
||||
let mut sig_tys = Vec::new();
|
||||
|
||||
for (arg_pat, arg_type) in args.iter().zip(arg_types.iter()) {
|
||||
let expected = if let Some(type_ref) = arg_type {
|
||||
self.make_ty(type_ref)
|
||||
} else {
|
||||
Ty::Unknown
|
||||
};
|
||||
let arg_ty = self.infer_pat(*arg_pat, &expected, BindingMode::default());
|
||||
sig_tys.push(arg_ty);
|
||||
}
|
||||
|
||||
// add return type
|
||||
let ret_ty = self.new_type_var();
|
||||
sig_tys.push(ret_ty.clone());
|
||||
let sig_ty = Ty::apply(
|
||||
TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1 },
|
||||
Substs(sig_tys.into()),
|
||||
);
|
||||
let closure_ty = Ty::apply_one(
|
||||
TypeCtor::Closure { def: self.body.owner(), expr: tgt_expr },
|
||||
sig_ty,
|
||||
);
|
||||
|
||||
// Eagerly try to relate the closure type with the expected
|
||||
// type, otherwise we often won't have enough information to
|
||||
// infer the body.
|
||||
self.coerce(&closure_ty, &expected.ty);
|
||||
|
||||
self.infer_expr(*body, &Expectation::has_type(ret_ty));
|
||||
closure_ty
|
||||
}
|
||||
Expr::Call { callee, args } => {
|
||||
let callee_ty = self.infer_expr(*callee, &Expectation::none());
|
||||
let (param_tys, ret_ty) = match callee_ty.callable_sig(self.db) {
|
||||
Some(sig) => (sig.params().to_vec(), sig.ret().clone()),
|
||||
None => {
|
||||
// Not callable
|
||||
// FIXME: report an error
|
||||
(Vec::new(), Ty::Unknown)
|
||||
}
|
||||
};
|
||||
self.register_obligations_for_call(&callee_ty);
|
||||
self.check_call_arguments(args, ¶m_tys);
|
||||
let ret_ty = self.normalize_associated_types_in(ret_ty);
|
||||
ret_ty
|
||||
}
|
||||
Expr::MethodCall { receiver, args, method_name, generic_args } => self
|
||||
.infer_method_call(tgt_expr, *receiver, &args, &method_name, generic_args.as_ref()),
|
||||
Expr::Match { expr, arms } => {
|
||||
let input_ty = self.infer_expr(*expr, &Expectation::none());
|
||||
|
||||
let mut result_ty = self.new_maybe_never_type_var();
|
||||
|
||||
for arm in arms {
|
||||
for &pat in &arm.pats {
|
||||
let _pat_ty = self.infer_pat(pat, &input_ty, BindingMode::default());
|
||||
}
|
||||
if let Some(guard_expr) = arm.guard {
|
||||
self.infer_expr(
|
||||
guard_expr,
|
||||
&Expectation::has_type(Ty::simple(TypeCtor::Bool)),
|
||||
);
|
||||
}
|
||||
|
||||
let arm_ty = self.infer_expr_inner(arm.expr, &expected);
|
||||
result_ty = self.coerce_merge_branch(&result_ty, &arm_ty);
|
||||
}
|
||||
|
||||
result_ty
|
||||
}
|
||||
Expr::Path(p) => {
|
||||
// FIXME this could be more efficient...
|
||||
let resolver = expr::resolver_for_expr(self.body.clone(), self.db, tgt_expr);
|
||||
self.infer_path(&resolver, p, tgt_expr.into()).unwrap_or(Ty::Unknown)
|
||||
}
|
||||
Expr::Continue => Ty::simple(TypeCtor::Never),
|
||||
Expr::Break { expr } => {
|
||||
if let Some(expr) = expr {
|
||||
// FIXME handle break with value
|
||||
self.infer_expr(*expr, &Expectation::none());
|
||||
}
|
||||
Ty::simple(TypeCtor::Never)
|
||||
}
|
||||
Expr::Return { expr } => {
|
||||
if let Some(expr) = expr {
|
||||
self.infer_expr(*expr, &Expectation::has_type(self.return_ty.clone()));
|
||||
}
|
||||
Ty::simple(TypeCtor::Never)
|
||||
}
|
||||
Expr::RecordLit { path, fields, spread } => {
|
||||
let (ty, def_id) = self.resolve_variant(path.as_ref());
|
||||
if let Some(variant) = def_id {
|
||||
self.write_variant_resolution(tgt_expr.into(), variant);
|
||||
}
|
||||
|
||||
self.unify(&ty, &expected.ty);
|
||||
|
||||
let substs = ty.substs().unwrap_or_else(Substs::empty);
|
||||
for (field_idx, field) in fields.iter().enumerate() {
|
||||
let field_ty = def_id
|
||||
.and_then(|it| match it.field(self.db, &field.name) {
|
||||
Some(field) => Some(field),
|
||||
None => {
|
||||
self.push_diagnostic(InferenceDiagnostic::NoSuchField {
|
||||
expr: tgt_expr,
|
||||
field: field_idx,
|
||||
});
|
||||
None
|
||||
}
|
||||
})
|
||||
.map_or(Ty::Unknown, |field| field.ty(self.db))
|
||||
.subst(&substs);
|
||||
self.infer_expr_coerce(field.expr, &Expectation::has_type(field_ty));
|
||||
}
|
||||
if let Some(expr) = spread {
|
||||
self.infer_expr(*expr, &Expectation::has_type(ty.clone()));
|
||||
}
|
||||
ty
|
||||
}
|
||||
Expr::Field { expr, name } => {
|
||||
let receiver_ty = self.infer_expr(*expr, &Expectation::none());
|
||||
let canonicalized = self.canonicalizer().canonicalize_ty(receiver_ty);
|
||||
let ty = autoderef::autoderef(
|
||||
self.db,
|
||||
&self.resolver.clone(),
|
||||
canonicalized.value.clone(),
|
||||
)
|
||||
.find_map(|derefed_ty| match canonicalized.decanonicalize_ty(derefed_ty.value) {
|
||||
Ty::Apply(a_ty) => match a_ty.ctor {
|
||||
TypeCtor::Tuple { .. } => name
|
||||
.as_tuple_index()
|
||||
.and_then(|idx| a_ty.parameters.0.get(idx).cloned()),
|
||||
TypeCtor::Adt(Adt::Struct(s)) => s.field(self.db, name).map(|field| {
|
||||
self.write_field_resolution(tgt_expr, field);
|
||||
field.ty(self.db).subst(&a_ty.parameters)
|
||||
}),
|
||||
_ => None,
|
||||
},
|
||||
_ => None,
|
||||
})
|
||||
.unwrap_or(Ty::Unknown);
|
||||
let ty = self.insert_type_vars(ty);
|
||||
self.normalize_associated_types_in(ty)
|
||||
}
|
||||
Expr::Await { expr } => {
|
||||
let inner_ty = self.infer_expr(*expr, &Expectation::none());
|
||||
let ty = match self.resolve_future_future_output() {
|
||||
Some(future_future_output_alias) => {
|
||||
let ty = self.new_type_var();
|
||||
let projection = ProjectionPredicate {
|
||||
ty: ty.clone(),
|
||||
projection_ty: ProjectionTy {
|
||||
associated_ty: future_future_output_alias,
|
||||
parameters: Substs::single(inner_ty),
|
||||
},
|
||||
};
|
||||
self.obligations.push(Obligation::Projection(projection));
|
||||
self.resolve_ty_as_possible(&mut vec![], ty)
|
||||
}
|
||||
None => Ty::Unknown,
|
||||
};
|
||||
ty
|
||||
}
|
||||
Expr::Try { expr } => {
|
||||
let inner_ty = self.infer_expr(*expr, &Expectation::none());
|
||||
let ty = match self.resolve_ops_try_ok() {
|
||||
Some(ops_try_ok_alias) => {
|
||||
let ty = self.new_type_var();
|
||||
let projection = ProjectionPredicate {
|
||||
ty: ty.clone(),
|
||||
projection_ty: ProjectionTy {
|
||||
associated_ty: ops_try_ok_alias,
|
||||
parameters: Substs::single(inner_ty),
|
||||
},
|
||||
};
|
||||
self.obligations.push(Obligation::Projection(projection));
|
||||
self.resolve_ty_as_possible(&mut vec![], ty)
|
||||
}
|
||||
None => Ty::Unknown,
|
||||
};
|
||||
ty
|
||||
}
|
||||
Expr::Cast { expr, type_ref } => {
|
||||
let _inner_ty = self.infer_expr(*expr, &Expectation::none());
|
||||
let cast_ty = self.make_ty(type_ref);
|
||||
// FIXME check the cast...
|
||||
cast_ty
|
||||
}
|
||||
Expr::Ref { expr, mutability } => {
|
||||
let expectation =
|
||||
if let Some((exp_inner, exp_mutability)) = &expected.ty.as_reference() {
|
||||
if *exp_mutability == Mutability::Mut && *mutability == Mutability::Shared {
|
||||
// FIXME: throw type error - expected mut reference but found shared ref,
|
||||
// which cannot be coerced
|
||||
}
|
||||
Expectation::has_type(Ty::clone(exp_inner))
|
||||
} else {
|
||||
Expectation::none()
|
||||
};
|
||||
// FIXME reference coercions etc.
|
||||
let inner_ty = self.infer_expr(*expr, &expectation);
|
||||
Ty::apply_one(TypeCtor::Ref(*mutability), inner_ty)
|
||||
}
|
||||
Expr::Box { expr } => {
|
||||
let inner_ty = self.infer_expr(*expr, &Expectation::none());
|
||||
if let Some(box_) = self.resolve_boxed_box() {
|
||||
Ty::apply_one(TypeCtor::Adt(box_), inner_ty)
|
||||
} else {
|
||||
Ty::Unknown
|
||||
}
|
||||
}
|
||||
Expr::UnaryOp { expr, op } => {
|
||||
let inner_ty = self.infer_expr(*expr, &Expectation::none());
|
||||
match op {
|
||||
UnaryOp::Deref => {
|
||||
let canonicalized = self.canonicalizer().canonicalize_ty(inner_ty);
|
||||
if let Some(derefed_ty) =
|
||||
autoderef::deref(self.db, &self.resolver, &canonicalized.value)
|
||||
{
|
||||
canonicalized.decanonicalize_ty(derefed_ty.value)
|
||||
} else {
|
||||
Ty::Unknown
|
||||
}
|
||||
}
|
||||
UnaryOp::Neg => {
|
||||
match &inner_ty {
|
||||
Ty::Apply(a_ty) => match a_ty.ctor {
|
||||
TypeCtor::Int(primitive::UncertainIntTy::Unknown)
|
||||
| TypeCtor::Int(primitive::UncertainIntTy::Known(
|
||||
primitive::IntTy {
|
||||
signedness: primitive::Signedness::Signed,
|
||||
..
|
||||
},
|
||||
))
|
||||
| TypeCtor::Float(..) => inner_ty,
|
||||
_ => Ty::Unknown,
|
||||
},
|
||||
Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => {
|
||||
inner_ty
|
||||
}
|
||||
// FIXME: resolve ops::Neg trait
|
||||
_ => Ty::Unknown,
|
||||
}
|
||||
}
|
||||
UnaryOp::Not => {
|
||||
match &inner_ty {
|
||||
Ty::Apply(a_ty) => match a_ty.ctor {
|
||||
TypeCtor::Bool | TypeCtor::Int(_) => inner_ty,
|
||||
_ => Ty::Unknown,
|
||||
},
|
||||
Ty::Infer(InferTy::IntVar(..)) => inner_ty,
|
||||
// FIXME: resolve ops::Not trait for inner_ty
|
||||
_ => Ty::Unknown,
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
Expr::BinaryOp { lhs, rhs, op } => match op {
|
||||
Some(op) => {
|
||||
let lhs_expectation = match op {
|
||||
BinaryOp::LogicOp(..) => Expectation::has_type(Ty::simple(TypeCtor::Bool)),
|
||||
_ => Expectation::none(),
|
||||
};
|
||||
let lhs_ty = self.infer_expr(*lhs, &lhs_expectation);
|
||||
// FIXME: find implementation of trait corresponding to operation
|
||||
// symbol and resolve associated `Output` type
|
||||
let rhs_expectation = op::binary_op_rhs_expectation(*op, lhs_ty);
|
||||
let rhs_ty = self.infer_expr(*rhs, &Expectation::has_type(rhs_expectation));
|
||||
|
||||
// FIXME: similar as above, return ty is often associated trait type
|
||||
op::binary_op_return_ty(*op, rhs_ty)
|
||||
}
|
||||
_ => Ty::Unknown,
|
||||
},
|
||||
Expr::Index { base, index } => {
|
||||
let _base_ty = self.infer_expr(*base, &Expectation::none());
|
||||
let _index_ty = self.infer_expr(*index, &Expectation::none());
|
||||
// FIXME: use `std::ops::Index::Output` to figure out the real return type
|
||||
Ty::Unknown
|
||||
}
|
||||
Expr::Tuple { exprs } => {
|
||||
let mut tys = match &expected.ty {
|
||||
ty_app!(TypeCtor::Tuple { .. }, st) => st
|
||||
.iter()
|
||||
.cloned()
|
||||
.chain(repeat_with(|| self.new_type_var()))
|
||||
.take(exprs.len())
|
||||
.collect::<Vec<_>>(),
|
||||
_ => (0..exprs.len()).map(|_| self.new_type_var()).collect(),
|
||||
};
|
||||
|
||||
for (expr, ty) in exprs.iter().zip(tys.iter_mut()) {
|
||||
self.infer_expr_coerce(*expr, &Expectation::has_type(ty.clone()));
|
||||
}
|
||||
|
||||
Ty::apply(TypeCtor::Tuple { cardinality: tys.len() as u16 }, Substs(tys.into()))
|
||||
}
|
||||
Expr::Array(array) => {
|
||||
let elem_ty = match &expected.ty {
|
||||
ty_app!(TypeCtor::Array, st) | ty_app!(TypeCtor::Slice, st) => {
|
||||
st.as_single().clone()
|
||||
}
|
||||
_ => self.new_type_var(),
|
||||
};
|
||||
|
||||
match array {
|
||||
Array::ElementList(items) => {
|
||||
for expr in items.iter() {
|
||||
self.infer_expr_coerce(*expr, &Expectation::has_type(elem_ty.clone()));
|
||||
}
|
||||
}
|
||||
Array::Repeat { initializer, repeat } => {
|
||||
self.infer_expr_coerce(
|
||||
*initializer,
|
||||
&Expectation::has_type(elem_ty.clone()),
|
||||
);
|
||||
self.infer_expr(
|
||||
*repeat,
|
||||
&Expectation::has_type(Ty::simple(TypeCtor::Int(
|
||||
primitive::UncertainIntTy::Known(primitive::IntTy::usize()),
|
||||
))),
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
Ty::apply_one(TypeCtor::Array, elem_ty)
|
||||
}
|
||||
Expr::Literal(lit) => match lit {
|
||||
Literal::Bool(..) => Ty::simple(TypeCtor::Bool),
|
||||
Literal::String(..) => {
|
||||
Ty::apply_one(TypeCtor::Ref(Mutability::Shared), Ty::simple(TypeCtor::Str))
|
||||
}
|
||||
Literal::ByteString(..) => {
|
||||
let byte_type = Ty::simple(TypeCtor::Int(primitive::UncertainIntTy::Known(
|
||||
primitive::IntTy::u8(),
|
||||
)));
|
||||
let slice_type = Ty::apply_one(TypeCtor::Slice, byte_type);
|
||||
Ty::apply_one(TypeCtor::Ref(Mutability::Shared), slice_type)
|
||||
}
|
||||
Literal::Char(..) => Ty::simple(TypeCtor::Char),
|
||||
Literal::Int(_v, ty) => Ty::simple(TypeCtor::Int(*ty)),
|
||||
Literal::Float(_v, ty) => Ty::simple(TypeCtor::Float(*ty)),
|
||||
},
|
||||
};
|
||||
// use a new type variable if we got Ty::Unknown here
|
||||
let ty = self.insert_type_vars_shallow(ty);
|
||||
let ty = self.resolve_ty_as_possible(&mut vec![], ty);
|
||||
self.write_expr_ty(tgt_expr, ty.clone());
|
||||
ty
|
||||
}
|
||||
|
||||
fn infer_block(
|
||||
&mut self,
|
||||
statements: &[Statement],
|
||||
tail: Option<ExprId>,
|
||||
expected: &Expectation,
|
||||
) -> Ty {
|
||||
let mut diverges = false;
|
||||
for stmt in statements {
|
||||
match stmt {
|
||||
Statement::Let { pat, type_ref, initializer } => {
|
||||
let decl_ty =
|
||||
type_ref.as_ref().map(|tr| self.make_ty(tr)).unwrap_or(Ty::Unknown);
|
||||
|
||||
// Always use the declared type when specified
|
||||
let mut ty = decl_ty.clone();
|
||||
|
||||
if let Some(expr) = initializer {
|
||||
let actual_ty =
|
||||
self.infer_expr_coerce(*expr, &Expectation::has_type(decl_ty.clone()));
|
||||
if decl_ty == Ty::Unknown {
|
||||
ty = actual_ty;
|
||||
}
|
||||
}
|
||||
|
||||
let ty = self.resolve_ty_as_possible(&mut vec![], ty);
|
||||
self.infer_pat(*pat, &ty, BindingMode::default());
|
||||
}
|
||||
Statement::Expr(expr) => {
|
||||
if let ty_app!(TypeCtor::Never) = self.infer_expr(*expr, &Expectation::none()) {
|
||||
diverges = true;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
let ty = if let Some(expr) = tail {
|
||||
self.infer_expr_coerce(expr, expected)
|
||||
} else {
|
||||
self.coerce(&Ty::unit(), &expected.ty);
|
||||
Ty::unit()
|
||||
};
|
||||
if diverges {
|
||||
Ty::simple(TypeCtor::Never)
|
||||
} else {
|
||||
ty
|
||||
}
|
||||
}
|
||||
|
||||
fn infer_method_call(
|
||||
&mut self,
|
||||
tgt_expr: ExprId,
|
||||
receiver: ExprId,
|
||||
args: &[ExprId],
|
||||
method_name: &Name,
|
||||
generic_args: Option<&GenericArgs>,
|
||||
) -> Ty {
|
||||
let receiver_ty = self.infer_expr(receiver, &Expectation::none());
|
||||
let canonicalized_receiver = self.canonicalizer().canonicalize_ty(receiver_ty.clone());
|
||||
let resolved = method_resolution::lookup_method(
|
||||
&canonicalized_receiver.value,
|
||||
self.db,
|
||||
method_name,
|
||||
&self.resolver,
|
||||
);
|
||||
let (derefed_receiver_ty, method_ty, def_generics) = match resolved {
|
||||
Some((ty, func)) => {
|
||||
let ty = canonicalized_receiver.decanonicalize_ty(ty);
|
||||
self.write_method_resolution(tgt_expr, func);
|
||||
(
|
||||
ty,
|
||||
self.db.type_for_def(func.into(), Namespace::Values),
|
||||
Some(func.generic_params(self.db)),
|
||||
)
|
||||
}
|
||||
None => (receiver_ty, Ty::Unknown, None),
|
||||
};
|
||||
let substs = self.substs_for_method_call(def_generics, generic_args, &derefed_receiver_ty);
|
||||
let method_ty = method_ty.apply_substs(substs);
|
||||
let method_ty = self.insert_type_vars(method_ty);
|
||||
self.register_obligations_for_call(&method_ty);
|
||||
let (expected_receiver_ty, param_tys, ret_ty) = match method_ty.callable_sig(self.db) {
|
||||
Some(sig) => {
|
||||
if !sig.params().is_empty() {
|
||||
(sig.params()[0].clone(), sig.params()[1..].to_vec(), sig.ret().clone())
|
||||
} else {
|
||||
(Ty::Unknown, Vec::new(), sig.ret().clone())
|
||||
}
|
||||
}
|
||||
None => (Ty::Unknown, Vec::new(), Ty::Unknown),
|
||||
};
|
||||
// Apply autoref so the below unification works correctly
|
||||
// FIXME: return correct autorefs from lookup_method
|
||||
let actual_receiver_ty = match expected_receiver_ty.as_reference() {
|
||||
Some((_, mutability)) => Ty::apply_one(TypeCtor::Ref(mutability), derefed_receiver_ty),
|
||||
_ => derefed_receiver_ty,
|
||||
};
|
||||
self.unify(&expected_receiver_ty, &actual_receiver_ty);
|
||||
|
||||
self.check_call_arguments(args, ¶m_tys);
|
||||
let ret_ty = self.normalize_associated_types_in(ret_ty);
|
||||
ret_ty
|
||||
}
|
||||
|
||||
fn check_call_arguments(&mut self, args: &[ExprId], param_tys: &[Ty]) {
|
||||
// Quoting https://github.com/rust-lang/rust/blob/6ef275e6c3cb1384ec78128eceeb4963ff788dca/src/librustc_typeck/check/mod.rs#L3325 --
|
||||
// We do this in a pretty awful way: first we type-check any arguments
|
||||
// that are not closures, then we type-check the closures. This is so
|
||||
// that we have more information about the types of arguments when we
|
||||
// type-check the functions. This isn't really the right way to do this.
|
||||
for &check_closures in &[false, true] {
|
||||
let param_iter = param_tys.iter().cloned().chain(repeat(Ty::Unknown));
|
||||
for (&arg, param_ty) in args.iter().zip(param_iter) {
|
||||
let is_closure = match &self.body[arg] {
|
||||
Expr::Lambda { .. } => true,
|
||||
_ => false,
|
||||
};
|
||||
|
||||
if is_closure != check_closures {
|
||||
continue;
|
||||
}
|
||||
|
||||
let param_ty = self.normalize_associated_types_in(param_ty);
|
||||
self.infer_expr_coerce(arg, &Expectation::has_type(param_ty.clone()));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn substs_for_method_call(
|
||||
&mut self,
|
||||
def_generics: Option<Arc<GenericParams>>,
|
||||
generic_args: Option<&GenericArgs>,
|
||||
receiver_ty: &Ty,
|
||||
) -> Substs {
|
||||
let (parent_param_count, param_count) =
|
||||
def_generics.as_ref().map_or((0, 0), |g| (g.count_parent_params(), g.params.len()));
|
||||
let mut substs = Vec::with_capacity(parent_param_count + param_count);
|
||||
// Parent arguments are unknown, except for the receiver type
|
||||
if let Some(parent_generics) = def_generics.and_then(|p| p.parent_params.clone()) {
|
||||
for param in &parent_generics.params {
|
||||
if param.name == name::SELF_TYPE {
|
||||
substs.push(receiver_ty.clone());
|
||||
} else {
|
||||
substs.push(Ty::Unknown);
|
||||
}
|
||||
}
|
||||
}
|
||||
// handle provided type arguments
|
||||
if let Some(generic_args) = generic_args {
|
||||
// if args are provided, it should be all of them, but we can't rely on that
|
||||
for arg in generic_args.args.iter().take(param_count) {
|
||||
match arg {
|
||||
GenericArg::Type(type_ref) => {
|
||||
let ty = self.make_ty(type_ref);
|
||||
substs.push(ty);
|
||||
}
|
||||
}
|
||||
}
|
||||
};
|
||||
let supplied_params = substs.len();
|
||||
for _ in supplied_params..parent_param_count + param_count {
|
||||
substs.push(Ty::Unknown);
|
||||
}
|
||||
assert_eq!(substs.len(), parent_param_count + param_count);
|
||||
Substs(substs.into())
|
||||
}
|
||||
|
||||
fn register_obligations_for_call(&mut self, callable_ty: &Ty) {
|
||||
if let Ty::Apply(a_ty) = callable_ty {
|
||||
if let TypeCtor::FnDef(def) = a_ty.ctor {
|
||||
let generic_predicates = self.db.generic_predicates(def.into());
|
||||
for predicate in generic_predicates.iter() {
|
||||
let predicate = predicate.clone().subst(&a_ty.parameters);
|
||||
if let Some(obligation) = Obligation::from_predicate(predicate) {
|
||||
self.obligations.push(obligation);
|
||||
}
|
||||
}
|
||||
// add obligation for trait implementation, if this is a trait method
|
||||
match def {
|
||||
CallableDef::Function(f) => {
|
||||
if let Some(trait_) = f.parent_trait(self.db) {
|
||||
// construct a TraitDef
|
||||
let substs = a_ty.parameters.prefix(
|
||||
trait_.generic_params(self.db).count_params_including_parent(),
|
||||
);
|
||||
self.obligations.push(Obligation::Trait(TraitRef { trait_, substs }));
|
||||
}
|
||||
}
|
||||
CallableDef::Struct(_) | CallableDef::EnumVariant(_) => {}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
180
crates/ra_hir/src/ty/infer/pat.rs
Normal file
180
crates/ra_hir/src/ty/infer/pat.rs
Normal file
@ -0,0 +1,180 @@
|
||||
//! Type inference for patterns.
|
||||
|
||||
use std::iter::repeat;
|
||||
use std::sync::Arc;
|
||||
|
||||
use test_utils::tested_by;
|
||||
|
||||
use super::{BindingMode, InferenceContext};
|
||||
use crate::{
|
||||
db::HirDatabase,
|
||||
expr::{BindingAnnotation, Pat, PatId, RecordFieldPat},
|
||||
ty::{Mutability, Substs, Ty, TypeCtor, TypeWalk},
|
||||
Name, Path,
|
||||
};
|
||||
|
||||
impl<'a, D: HirDatabase> InferenceContext<'a, D> {
|
||||
fn infer_tuple_struct_pat(
|
||||
&mut self,
|
||||
path: Option<&Path>,
|
||||
subpats: &[PatId],
|
||||
expected: &Ty,
|
||||
default_bm: BindingMode,
|
||||
) -> Ty {
|
||||
let (ty, def) = self.resolve_variant(path);
|
||||
|
||||
self.unify(&ty, expected);
|
||||
|
||||
let substs = ty.substs().unwrap_or_else(Substs::empty);
|
||||
|
||||
for (i, &subpat) in subpats.iter().enumerate() {
|
||||
let expected_ty = def
|
||||
.and_then(|d| d.field(self.db, &Name::new_tuple_field(i)))
|
||||
.map_or(Ty::Unknown, |field| field.ty(self.db))
|
||||
.subst(&substs);
|
||||
let expected_ty = self.normalize_associated_types_in(expected_ty);
|
||||
self.infer_pat(subpat, &expected_ty, default_bm);
|
||||
}
|
||||
|
||||
ty
|
||||
}
|
||||
|
||||
fn infer_record_pat(
|
||||
&mut self,
|
||||
path: Option<&Path>,
|
||||
subpats: &[RecordFieldPat],
|
||||
expected: &Ty,
|
||||
default_bm: BindingMode,
|
||||
id: PatId,
|
||||
) -> Ty {
|
||||
let (ty, def) = self.resolve_variant(path);
|
||||
if let Some(variant) = def {
|
||||
self.write_variant_resolution(id.into(), variant);
|
||||
}
|
||||
|
||||
self.unify(&ty, expected);
|
||||
|
||||
let substs = ty.substs().unwrap_or_else(Substs::empty);
|
||||
|
||||
for subpat in subpats {
|
||||
let matching_field = def.and_then(|it| it.field(self.db, &subpat.name));
|
||||
let expected_ty =
|
||||
matching_field.map_or(Ty::Unknown, |field| field.ty(self.db)).subst(&substs);
|
||||
let expected_ty = self.normalize_associated_types_in(expected_ty);
|
||||
self.infer_pat(subpat.pat, &expected_ty, default_bm);
|
||||
}
|
||||
|
||||
ty
|
||||
}
|
||||
|
||||
pub(super) fn infer_pat(
|
||||
&mut self,
|
||||
pat: PatId,
|
||||
mut expected: &Ty,
|
||||
mut default_bm: BindingMode,
|
||||
) -> Ty {
|
||||
let body = Arc::clone(&self.body); // avoid borrow checker problem
|
||||
|
||||
let is_non_ref_pat = match &body[pat] {
|
||||
Pat::Tuple(..)
|
||||
| Pat::TupleStruct { .. }
|
||||
| Pat::Record { .. }
|
||||
| Pat::Range { .. }
|
||||
| Pat::Slice { .. } => true,
|
||||
// FIXME: Path/Lit might actually evaluate to ref, but inference is unimplemented.
|
||||
Pat::Path(..) | Pat::Lit(..) => true,
|
||||
Pat::Wild | Pat::Bind { .. } | Pat::Ref { .. } | Pat::Missing => false,
|
||||
};
|
||||
if is_non_ref_pat {
|
||||
while let Some((inner, mutability)) = expected.as_reference() {
|
||||
expected = inner;
|
||||
default_bm = match default_bm {
|
||||
BindingMode::Move => BindingMode::Ref(mutability),
|
||||
BindingMode::Ref(Mutability::Shared) => BindingMode::Ref(Mutability::Shared),
|
||||
BindingMode::Ref(Mutability::Mut) => BindingMode::Ref(mutability),
|
||||
}
|
||||
}
|
||||
} else if let Pat::Ref { .. } = &body[pat] {
|
||||
tested_by!(match_ergonomics_ref);
|
||||
// When you encounter a `&pat` pattern, reset to Move.
|
||||
// This is so that `w` is by value: `let (_, &w) = &(1, &2);`
|
||||
default_bm = BindingMode::Move;
|
||||
}
|
||||
|
||||
// Lose mutability.
|
||||
let default_bm = default_bm;
|
||||
let expected = expected;
|
||||
|
||||
let ty = match &body[pat] {
|
||||
Pat::Tuple(ref args) => {
|
||||
let expectations = match expected.as_tuple() {
|
||||
Some(parameters) => &*parameters.0,
|
||||
_ => &[],
|
||||
};
|
||||
let expectations_iter = expectations.iter().chain(repeat(&Ty::Unknown));
|
||||
|
||||
let inner_tys = args
|
||||
.iter()
|
||||
.zip(expectations_iter)
|
||||
.map(|(&pat, ty)| self.infer_pat(pat, ty, default_bm))
|
||||
.collect();
|
||||
|
||||
Ty::apply(TypeCtor::Tuple { cardinality: args.len() as u16 }, Substs(inner_tys))
|
||||
}
|
||||
Pat::Ref { pat, mutability } => {
|
||||
let expectation = match expected.as_reference() {
|
||||
Some((inner_ty, exp_mut)) => {
|
||||
if *mutability != exp_mut {
|
||||
// FIXME: emit type error?
|
||||
}
|
||||
inner_ty
|
||||
}
|
||||
_ => &Ty::Unknown,
|
||||
};
|
||||
let subty = self.infer_pat(*pat, expectation, default_bm);
|
||||
Ty::apply_one(TypeCtor::Ref(*mutability), subty)
|
||||
}
|
||||
Pat::TupleStruct { path: p, args: subpats } => {
|
||||
self.infer_tuple_struct_pat(p.as_ref(), subpats, expected, default_bm)
|
||||
}
|
||||
Pat::Record { path: p, args: fields } => {
|
||||
self.infer_record_pat(p.as_ref(), fields, expected, default_bm, pat)
|
||||
}
|
||||
Pat::Path(path) => {
|
||||
// FIXME use correct resolver for the surrounding expression
|
||||
let resolver = self.resolver.clone();
|
||||
self.infer_path(&resolver, &path, pat.into()).unwrap_or(Ty::Unknown)
|
||||
}
|
||||
Pat::Bind { mode, name: _, subpat } => {
|
||||
let mode = if mode == &BindingAnnotation::Unannotated {
|
||||
default_bm
|
||||
} else {
|
||||
BindingMode::convert(*mode)
|
||||
};
|
||||
let inner_ty = if let Some(subpat) = subpat {
|
||||
self.infer_pat(*subpat, expected, default_bm)
|
||||
} else {
|
||||
expected.clone()
|
||||
};
|
||||
let inner_ty = self.insert_type_vars_shallow(inner_ty);
|
||||
|
||||
let bound_ty = match mode {
|
||||
BindingMode::Ref(mutability) => {
|
||||
Ty::apply_one(TypeCtor::Ref(mutability), inner_ty.clone())
|
||||
}
|
||||
BindingMode::Move => inner_ty.clone(),
|
||||
};
|
||||
let bound_ty = self.resolve_ty_as_possible(&mut vec![], bound_ty);
|
||||
self.write_pat_ty(pat, bound_ty);
|
||||
return inner_ty;
|
||||
}
|
||||
_ => Ty::Unknown,
|
||||
};
|
||||
// use a new type variable if we got Ty::Unknown here
|
||||
let ty = self.insert_type_vars_shallow(ty);
|
||||
self.unify(&ty, expected);
|
||||
let ty = self.resolve_ty_as_possible(&mut vec![], ty);
|
||||
self.write_pat_ty(pat, ty.clone());
|
||||
ty
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user