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Don't allocate in associated_type_shorthand_candidates

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This commit is contained in:
Lukas Wirth 2021-04-02 02:09:12 +02:00
parent 5ef0c7a213
commit c24753ae5d
1 changed files with 33 additions and 36 deletions
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69
crates/hir_ty/src/lower.rs
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@ -821,24 +821,38 @@ pub fn associated_type_shorthand_candidates<R>(
res: TypeNs,
mut cb: impl FnMut(&Name, &TraitRef, TypeAliasId) -> Option<R>,
) -> Option<R> {
let traits_from_env: Vec<_> = match res {
TypeNs::SelfType(impl_id) => match db.impl_trait(impl_id) {
None => vec![],
// FIXME: how to correctly handle higher-ranked bounds here?
Some(trait_ref) => vec![trait_ref.value.shift_bound_vars_out(DebruijnIndex::ONE)],
},
let mut search = |t| {
for t in all_super_trait_refs(db, t) {
let data = db.trait_data(t.hir_trait_id());
for (name, assoc_id) in &data.items {
if let AssocItemId::TypeAliasId(alias) = assoc_id {
if let Some(result) = cb(name, &t, *alias) {
return Some(result);
}
}
}
}
None
};
match res {
// FIXME: how to correctly handle higher-ranked bounds here?
TypeNs::SelfType(impl_id) => {
search(db.impl_trait(impl_id)?.value.shift_bound_vars_out(DebruijnIndex::ONE))
}
TypeNs::GenericParam(param_id) => {
let predicates = db.generic_predicates_for_param(param_id);
let mut traits_: Vec<_> = predicates
.iter()
.filter_map(|pred| match &pred.value.value {
// FIXME: how to correctly handle higher-ranked bounds here?
WhereClause::Implemented(tr) => {
Some(tr.clone().shift_bound_vars_out(DebruijnIndex::ONE))
}
_ => None,
})
.collect();
let res = predicates.iter().find_map(|pred| match &pred.value.value {
// FIXME: how to correctly handle higher-ranked bounds here?
WhereClause::Implemented(tr) => {
search(tr.clone().shift_bound_vars_out(DebruijnIndex::ONE))
}
_ => None,
});
if let res @ Some(_) = res {
return res;
}
// Handle `Self::Type` referring to own associated type in trait definitions
if let GenericDefId::TraitId(trait_id) = param_id.parent {
let generics = generics(db.upcast(), trait_id.into());
@ -849,30 +863,13 @@ pub fn associated_type_shorthand_candidates<R>(
trait_id: to_chalk_trait_id(trait_id),
substitution: Substitution::bound_vars(&generics, DebruijnIndex::INNERMOST),
};
traits_.push(trait_ref);
return search(trait_ref);
}
}
traits_
}
_ => vec![],
};
for t in traits_from_env.into_iter().flat_map(move |t| all_super_trait_refs(db, t)) {
let data = db.trait_data(t.hir_trait_id());
for (name, assoc_id) in &data.items {
match assoc_id {
AssocItemId::TypeAliasId(alias) => {
if let Some(result) = cb(name, &t, *alias) {
return Some(result);
}
}
AssocItemId::FunctionId(_) | AssocItemId::ConstId(_) => {}
}
None
}
_ => None,
}
None
}
/// Build the type of all specific fields of a struct or enum variant.