language-servers/rust-analyzer
1
0
Fork 0
mirror of https://github.com/rust-lang/rust-analyzer.git synced 2025-09-27 04:19:13 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

Add diagnostic for _ expressions (typed holes)

Browse source
This commit is contained in:
Lukas Wirth 2023-05-28 13:30:34 +02:00
parent 150082b0e3
commit 8bc826dd53
9 changed files with 368 additions and 61 deletions
Download patch file Download diff file Expand all files Collapse all files

25
crates/hir-ty/src/infer/expr.rs
View file

@ -874,9 +874,15 @@ impl<'a> InferenceContext<'a> {
},
Expr::Underscore => {
// Underscore expressions may only appear in assignee expressions,
// which are handled by `infer_assignee_expr()`, so any underscore
// expression reaching this branch is an error.
self.err_ty()
// which are handled by `infer_assignee_expr()`.
// Any other underscore expression is an error, we render a specialized diagnostic
// to let the user know what type is expected though.
let expected = expected.to_option(&mut self.table).unwrap_or_else(|| self.err_ty());
self.push_diagnostic(InferenceDiagnostic::TypedHole {
expr: tgt_expr,
expected: expected.clone(),
});
expected
}
};
// use a new type variable if we got unknown here
@ -1001,12 +1007,13 @@ impl<'a> InferenceContext<'a> {
}
&Array::Repeat { initializer, repeat } => {
self.infer_expr_coerce(initializer, &Expectation::has_type(elem_ty.clone()));
self.infer_expr(
repeat,
&Expectation::HasType(
TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(Interner),
),
);
let usize = TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(Interner);
match self.body[repeat] {
Expr::Underscore => {
self.write_expr_ty(repeat, usize);
}
_ => _ = self.infer_expr(repeat, &Expectation::HasType(usize)),
}
(
elem_ty,