Unnamed repository; edit this file 'description' to name the repository.
Implement `try{}` block type inference
Maybe Waffle 2022-12-29
parent ef303f2 · commit aaa682c
-rw-r--r--crates/hir-ty/src/infer/expr.rs17
-rw-r--r--crates/hir-ty/src/tests/simple.rs28
2 files changed, 27 insertions, 18 deletions
diff --git a/crates/hir-ty/src/infer/expr.rs b/crates/hir-ty/src/infer/expr.rs
index 0d3f15c3d5..d4050f9af4 100644
--- a/crates/hir-ty/src/infer/expr.rs
+++ b/crates/hir-ty/src/infer/expr.rs
@@ -152,11 +152,20 @@ impl<'a> InferenceContext<'a> {
.1
}
Expr::TryBlock { body } => {
- self.with_breakable_ctx(BreakableKind::Block, self.err_ty(), None, |this| {
- let _inner = this.infer_expr(*body, expected);
+ // The type that is returned from the try block
+ let try_ty = self.table.new_type_var();
+ if let Some(ty) = expected.only_has_type(&mut self.table) {
+ self.unify(&try_ty, &ty);
+ }
+
+ // The ok-ish type that is expected from the last expression
+ let ok_ty = self.resolve_associated_type(try_ty.clone(), self.resolve_ops_try_ok());
+
+ self.with_breakable_ctx(BreakableKind::Block, ok_ty.clone(), None, |this| {
+ this.infer_expr(*body, &Expectation::has_type(ok_ty));
});
- // FIXME should be std::result::Result<{inner}, _>
- self.err_ty()
+
+ try_ty
}
Expr::Async { body } => {
let ret_ty = self.table.new_type_var();
diff --git a/crates/hir-ty/src/tests/simple.rs b/crates/hir-ty/src/tests/simple.rs
index d7431443b8..146145523b 100644
--- a/crates/hir-ty/src/tests/simple.rs
+++ b/crates/hir-ty/src/tests/simple.rs
@@ -2064,17 +2064,17 @@ fn fn_pointer_return() {
fn block_modifiers_smoke_test() {
check_infer(
r#"
-//- minicore: future
+//- minicore: future, try
async fn main() {
let x = unsafe { 92 };
let y = async { async { () }.await };
- let z = try { () };
+ let z: core::ops::ControlFlow<(), _> = try { () };
let w = const { 92 };
let t = 'a: { 92 };
}
"#,
expect![[r#"
- 16..162 '{ ...2 }; }': ()
+ 16..193 '{ ...2 }; }': ()
26..27 'x': i32
30..43 'unsafe { 92 }': i32
30..43 'unsafe { 92 }': i32
@@ -2086,17 +2086,17 @@ async fn main() {
65..77 'async { () }': impl Future<Output = ()>
65..83 'async ....await': ()
73..75 '()': ()
- 95..96 'z': {unknown}
- 99..109 'try { () }': ()
- 99..109 'try { () }': {unknown}
- 105..107 '()': ()
- 119..120 'w': i32
- 123..135 'const { 92 }': i32
- 123..135 'const { 92 }': i32
- 131..133 '92': i32
- 145..146 't': i32
- 149..159 ''a: { 92 }': i32
- 155..157 '92': i32
+ 95..96 'z': ControlFlow<(), ()>
+ 130..140 'try { () }': ()
+ 130..140 'try { () }': ControlFlow<(), ()>
+ 136..138 '()': ()
+ 150..151 'w': i32
+ 154..166 'const { 92 }': i32
+ 154..166 'const { 92 }': i32
+ 162..164 '92': i32
+ 176..177 't': i32
+ 180..190 ''a: { 92 }': i32
+ 186..188 '92': i32
"#]],
)
}