bendns' repos / rust-analyzer
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fix: infer for-loop item type with `IntoIterator` and `Iterator`
Browse Source
Ryo Yoshida 2022-09-29
parent ad752bd · commit 6d8903a
Diffstat
-rw-r--r--crates/hir-expand/src/name.rs1
-rw-r--r--crates/hir-ty/src/infer.rs6
-rw-r--r--crates/hir-ty/src/infer/expr.rs4
-rw-r--r--crates/hir-ty/src/tests/traits.rs12
-rw-r--r--crates/ide/src/inlay_hints.rs9
5 files changed, 29 insertions, 3 deletions
diff --git a/crates/hir-expand/src/name.rs b/crates/hir-expand/src/name.rs
index 4ce21a5796..2679a1c360 100644
--- a/crates/hir-expand/src/name.rs
+++ b/crates/hir-expand/src/name.rs
@@ -263,6 +263,7 @@ pub mod known {
Iterator,
IntoIterator,
Item,
+ IntoIter,
Try,
Ok,
Future,
diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs
index 039824694a..25179afaca 100644
--- a/crates/hir-ty/src/infer.rs
+++ b/crates/hir-ty/src/infer.rs
@@ -883,6 +883,12 @@ impl<'a> InferenceContext<'a> {
fn resolve_into_iter_item(&self) -> Option<TypeAliasId> {
let path = path![core::iter::IntoIterator];
let trait_ = self.resolver.resolve_known_trait(self.db.upcast(), &path)?;
+ self.db.trait_data(trait_).associated_type_by_name(&name![IntoIter])
+ }
+
+ fn resolve_iterator_item(&self) -> Option<TypeAliasId> {
+ let path = path![core::iter::Iterator];
+ let trait_ = self.resolver.resolve_known_trait(self.db.upcast(), &path)?;
self.db.trait_data(trait_).associated_type_by_name(&name![Item])
}
diff --git a/crates/hir-ty/src/infer/expr.rs b/crates/hir-ty/src/infer/expr.rs
index e3d6be23e6..2643baf8a3 100644
--- a/crates/hir-ty/src/infer/expr.rs
+++ b/crates/hir-ty/src/infer/expr.rs
@@ -207,8 +207,10 @@ impl<'a> InferenceContext<'a> {
}
&Expr::For { iterable, body, pat, label } => {
let iterable_ty = self.infer_expr(iterable, &Expectation::none());
- let pat_ty =
+ let into_iter_ty =
self.resolve_associated_type(iterable_ty, self.resolve_into_iter_item());
+ let pat_ty =
+ self.resolve_associated_type(into_iter_ty, self.resolve_iterator_item());
self.infer_pat(pat, &pat_ty, BindingMode::default());
self.with_breakable_ctx(BreakableKind::Loop, self.err_ty(), label, |this| {
diff --git a/crates/hir-ty/src/tests/traits.rs b/crates/hir-ty/src/tests/traits.rs
index 21a8631976..555b6972fb 100644
--- a/crates/hir-ty/src/tests/traits.rs
+++ b/crates/hir-ty/src/tests/traits.rs
@@ -279,6 +279,10 @@ fn test() {
pub mod iter {
pub trait IntoIterator {
type Item;
+ type IntoIter: Iterator<Item = Self::Item>;
+ }
+ pub trait Iterator {
+ type Item;
}
}
pub mod prelude {
@@ -297,7 +301,13 @@ pub mod collections {
}
impl<T> IntoIterator for Vec<T> {
- type Item=T;
+ type Item = T;
+ type IntoIter = IntoIter<T>;
+ }
+
+ struct IntoIter<T> {}
+ impl<T> Iterator for IntoIter<T> {
+ type Item = T;
}
}
"#,
diff --git a/crates/ide/src/inlay_hints.rs b/crates/ide/src/inlay_hints.rs
index 08363d21e8..34d8bf67a3 100644
--- a/crates/ide/src/inlay_hints.rs
+++ b/crates/ide/src/inlay_hints.rs
@@ -2024,7 +2024,14 @@ impl<T> Vec<T> {
}
impl<T> IntoIterator for Vec<T> {
- type Item=T;
+ type Item = T;
+ type IntoIter = IntoIter<T>;
+}
+
+struct IntoIter<T> {}
+
+impl<T> Iterator for IntoIter<T> {
+ type Item = T;
}
fn main() {