Mirrors/rust-analyzer
2
0
Fork 0
mirror of https://github.com/rust-lang/rust-analyzer synced 2024-11-15 01:17:27 +00:00
Code Issues Projects Releases Packages Wiki Activity

Handle placeholder assoc types when Chalk produces them

Browse source
This commit is contained in:
Florian Diebold 2019-08-11 15:54:31 +02:00
parent 9d72b14cfe
commit 5af9691dc9
2 changed files with 67 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

49
crates/ra_hir/src/ty/tests.rs
View file

@ -3181,6 +3181,55 @@ fn test<T: Trait>(t: T) { (*t)<|>; }
assert_eq!(t, "i128");
}
#[test]
fn associated_type_placeholder() {
let t = type_at(
r#"
//- /main.rs
pub trait ApplyL {
type Out;
}
pub struct RefMutL<T>;
impl<T> ApplyL for RefMutL<T> {
type Out = <T as ApplyL>::Out;
}
fn test<T: ApplyL>() {
let y: <RefMutL<T> as ApplyL>::Out = no_matter;
y<|>;
}
"#,
);
// inside the generic function, the associated type gets normalized to a placeholder `ApplL::Out<T>` [https://rust-lang.github.io/rustc-guide/traits/associated-types.html#placeholder-associated-types].
// FIXME: fix type parameter names going missing when going through Chalk
assert_eq!(t, "ApplyL::Out<[missing name]>");
}
#[test]
fn associated_type_placeholder_2() {
let t = type_at(
r#"
//- /main.rs
pub trait ApplyL {
type Out;
}
fn foo<T: ApplyL>(t: T) -> <T as ApplyL>::Out;
fn test<T: ApplyL>(t: T) {
let y = foo(t);
y<|>;
}
"#,
);
// FIXME here Chalk doesn't normalize the type to a placeholder. I think we
// need to add a rule like Normalize(<T as ApplyL>::Out -> ApplyL::Out<T>)
// to the trait env ourselves here; probably Chalk can't do this by itself.
// assert_eq!(t, "ApplyL::Out<[missing name]>");
assert_eq!(t, "{unknown}");
}
fn type_at_pos(db: &MockDatabase, pos: FilePosition) -> String {
let file = db.parse(pos.file_id).ok().unwrap();
let expr = algo::find_node_at_offset::<ast::Expr>(file.syntax(), pos.offset).unwrap();

21
crates/ra_hir/src/ty/traits/chalk.rs
View file

@ -45,8 +45,17 @@ impl ToChalk for Ty {
fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Ty {
match self {
Ty::Apply(apply_ty) => {
let struct_id = apply_ty.ctor.to_chalk(db);
let name = TypeName::TypeKindId(struct_id.into());
let name = match apply_ty.ctor {
TypeCtor::AssociatedType(type_alias) => {
let type_id = type_alias.to_chalk(db);
TypeName::AssociatedType(type_id)
}
_ => {
// other TypeCtors get interned and turned into a chalk StructId
let struct_id = apply_ty.ctor.to_chalk(db);
TypeName::TypeKindId(struct_id.into())
}
};
let parameters = apply_ty.parameters.to_chalk(db);
chalk_ir::ApplicationTy { name, parameters }.cast()
}
@ -79,15 +88,21 @@ impl ToChalk for Ty {
fn from_chalk(db: &impl HirDatabase, chalk: chalk_ir::Ty) -> Self {
match chalk {
chalk_ir::Ty::Apply(apply_ty) => {
// FIXME this is kind of hacky due to the fact that
// TypeName::Placeholder is a Ty::Param on our side
match apply_ty.name {
TypeName::TypeKindId(TypeKindId::StructId(struct_id)) => {
let ctor = from_chalk(db, struct_id);
let parameters = from_chalk(db, apply_ty.parameters);
Ty::Apply(ApplicationTy { ctor, parameters })
}
TypeName::AssociatedType(type_id) => {
let ctor = TypeCtor::AssociatedType(from_chalk(db, type_id));
let parameters = from_chalk(db, apply_ty.parameters);
Ty::Apply(ApplicationTy { ctor, parameters })
}
// FIXME handle TypeKindId::Trait/Type here
TypeName::TypeKindId(_) => unimplemented!(),
TypeName::AssociatedType(_) => unimplemented!(),
TypeName::Placeholder(idx) => {
assert_eq!(idx.ui, UniverseIndex::ROOT);
Ty::Param { idx: idx.idx as u32, name: crate::Name::missing() }