Add `TraitRef` for HIR
@@ -2791,14 +2791,19 @@ impl Impl {
all
}
- // FIXME: the return type is wrong. This should be a hir version of
- // `TraitRef` (to account for parameters and qualifiers)
pub fn trait_(self, db: &dyn HirDatabase) -> Option<Trait> {
- let trait_ref = db.impl_trait(self.id)?.skip_binders().clone();
- let id = hir_ty::from_chalk_trait_id(trait_ref.trait_id);
+ let trait_ref = db.impl_trait(self.id)?;
+ let id = trait_ref.skip_binders().hir_trait_id();
Some(Trait { id })
}
+ pub fn trait_ref(self, db: &dyn HirDatabase) -> Option<TraitRef> {
+ let substs = TyBuilder::placeholder_subst(db, self.id);
+ let trait_ref = db.impl_trait(self.id)?.substitute(Interner, &substs);
+ let resolver = self.id.resolver(db.upcast());
+ Some(TraitRef::new_with_resolver(db, &resolver, trait_ref))
+ }
+
pub fn self_ty(self, db: &dyn HirDatabase) -> Type {
let resolver = self.id.resolver(db.upcast());
let substs = TyBuilder::placeholder_subst(db, self.id);
@@ -2824,6 +2829,48 @@ impl Impl {
}
}
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct TraitRef {
+ env: Arc<TraitEnvironment>,
+ trait_ref: hir_ty::TraitRef,
+}
+
+impl TraitRef {
+ pub(crate) fn new_with_resolver(
+ db: &dyn HirDatabase,
+ resolver: &Resolver,
+ trait_ref: hir_ty::TraitRef,
+ ) -> TraitRef {
+ let env = resolver.generic_def().map_or_else(
+ || Arc::new(TraitEnvironment::empty(resolver.krate())),
+ |d| db.trait_environment(d),
+ );
+ TraitRef { env, trait_ref }
+ }
+
+ pub fn trait_(&self) -> Trait {
+ let id = self.trait_ref.hir_trait_id();
+ Trait { id }
+ }
+
+ pub fn self_ty(&self) -> Type {
+ let ty = self.trait_ref.self_type_parameter(Interner);
+ Type { env: self.env.clone(), ty }
+ }
+
+ /// Returns `idx`-th argument of this trait reference if it is a type argument. Note that the
+ /// first argument is the `Self` type.
+ pub fn get_type_argument(&self, idx: usize) -> Option<Type> {
+ self.trait_ref
+ .substitution
+ .as_slice(Interner)
+ .get(idx)
+ .and_then(|arg| arg.ty(Interner))
+ .cloned()
+ .map(|ty| Type { env: self.env.clone(), ty })
+ }
+}
+
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct Type {
env: Arc<TraitEnvironment>,
