51 lines
1.8 KiB
Rust
51 lines
1.8 KiB
Rust
|
use hir_def::{
|
||
|
|
db::DefDatabase,
|
||
|
|
resolver::{HasResolver, TypeNs},
|
||
|
|
type_ref::TypeRef,
|
||
|
|
TraitId,
|
||
|
|
};
|
||
|
|
use hir_expand::name;
|
||
|
|
|
||
|
|
// FIXME: this is wrong, b/c it can't express `trait T: PartialEq<()>`.
|
||
|
|
// We should return a `TraitREf` here.
|
||
|
|
fn direct_super_traits(db: &impl DefDatabase, trait_: TraitId) -> Vec<TraitId> {
|
||
|
|
let resolver = trait_.resolver(db);
|
||
|
|
// returning the iterator directly doesn't easily work because of
|
||
|
|
// lifetime problems, but since there usually shouldn't be more than a
|
||
|
|
// few direct traits this should be fine (we could even use some kind of
|
||
|
|
// SmallVec if performance is a concern)
|
||
|
|
db.generic_params(trait_.into())
|
||
|
|
.where_predicates
|
||
|
|
.iter()
|
||
|
|
.filter_map(|pred| match &pred.type_ref {
|
||
|
|
TypeRef::Path(p) if p.as_ident() == Some(&name::SELF_TYPE) => pred.bound.as_path(),
|
||
|
|
_ => None,
|
||
|
|
})
|
||
|
|
.filter_map(|path| match resolver.resolve_path_in_type_ns_fully(db, path) {
|
||
|
|
Some(TypeNs::TraitId(t)) => Some(t),
|
||
|
|
_ => None,
|
||
|
|
})
|
||
|
|
.collect()
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Returns an iterator over the whole super trait hierarchy (including the
|
||
|
|
/// trait itself).
|
||
|
|
pub(crate) fn all_super_traits(db: &impl DefDatabase, trait_: TraitId) -> Vec<TraitId> {
|
||
|
|
// we need to take care a bit here to avoid infinite loops in case of cycles
|
||
|
|
// (i.e. if we have `trait A: B; trait B: A;`)
|
||
|
|
let mut result = vec![trait_];
|
||
|
|
let mut i = 0;
|
||
|
|
while i < result.len() {
|
||
|
|
let t = result[i];
|
||
|
|
// yeah this is quadratic, but trait hierarchies should be flat
|
||
|
|
// enough that this doesn't matter
|
||
|
|
for tt in direct_super_traits(db, t) {
|
||
|
|
if !result.contains(&tt) {
|
||
|
|
result.push(tt);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
i += 1;
|
||
|
|
}
|
||
|
|
result
|
||
|
|
}
|