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Diffstat (limited to 'crates/ra_hir/src/ty/utils.rs')
-rw-r--r-- | crates/ra_hir/src/ty/utils.rs | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/crates/ra_hir/src/ty/utils.rs b/crates/ra_hir/src/ty/utils.rs new file mode 100644 index 000000000..52994b9e3 --- /dev/null +++ b/crates/ra_hir/src/ty/utils.rs | |||
@@ -0,0 +1,63 @@ | |||
1 | //! Helper functions for working with def, which don't need to be a separate | ||
2 | //! query, but can't be computed directly from `*Data` (ie, which need a `db`). | ||
3 | |||
4 | use hir_def::{ | ||
5 | db::DefDatabase, | ||
6 | resolver::{HasResolver, TypeNs}, | ||
7 | type_ref::TypeRef, | ||
8 | TraitId, TypeAliasId, | ||
9 | }; | ||
10 | use hir_expand::name::{self, Name}; | ||
11 | |||
12 | // FIXME: this is wrong, b/c it can't express `trait T: PartialEq<()>`. | ||
13 | // We should return a `TraitREf` here. | ||
14 | fn direct_super_traits(db: &impl DefDatabase, trait_: TraitId) -> Vec<TraitId> { | ||
15 | let resolver = trait_.resolver(db); | ||
16 | // returning the iterator directly doesn't easily work because of | ||
17 | // lifetime problems, but since there usually shouldn't be more than a | ||
18 | // few direct traits this should be fine (we could even use some kind of | ||
19 | // SmallVec if performance is a concern) | ||
20 | db.generic_params(trait_.into()) | ||
21 | .where_predicates | ||
22 | .iter() | ||
23 | .filter_map(|pred| match &pred.type_ref { | ||
24 | TypeRef::Path(p) if p.as_ident() == Some(&name::SELF_TYPE) => pred.bound.as_path(), | ||
25 | _ => None, | ||
26 | }) | ||
27 | .filter_map(|path| match resolver.resolve_path_in_type_ns_fully(db, path) { | ||
28 | Some(TypeNs::TraitId(t)) => Some(t), | ||
29 | _ => None, | ||
30 | }) | ||
31 | .collect() | ||
32 | } | ||
33 | |||
34 | /// Returns an iterator over the whole super trait hierarchy (including the | ||
35 | /// trait itself). | ||
36 | pub(crate) fn all_super_traits(db: &impl DefDatabase, trait_: TraitId) -> Vec<TraitId> { | ||
37 | // we need to take care a bit here to avoid infinite loops in case of cycles | ||
38 | // (i.e. if we have `trait A: B; trait B: A;`) | ||
39 | let mut result = vec![trait_]; | ||
40 | let mut i = 0; | ||
41 | while i < result.len() { | ||
42 | let t = result[i]; | ||
43 | // yeah this is quadratic, but trait hierarchies should be flat | ||
44 | // enough that this doesn't matter | ||
45 | for tt in direct_super_traits(db, t) { | ||
46 | if !result.contains(&tt) { | ||
47 | result.push(tt); | ||
48 | } | ||
49 | } | ||
50 | i += 1; | ||
51 | } | ||
52 | result | ||
53 | } | ||
54 | |||
55 | pub(crate) fn associated_type_by_name_including_super_traits( | ||
56 | db: &impl DefDatabase, | ||
57 | trait_: TraitId, | ||
58 | name: &Name, | ||
59 | ) -> Option<TypeAliasId> { | ||
60 | all_super_traits(db, trait_) | ||
61 | .into_iter() | ||
62 | .find_map(|t| db.trait_data(t).associated_type_by_name(name)) | ||
63 | } | ||