Power up goto_implementation

by allowing it to be invoked on references of names, showing all (trait)
implementations of the given type in all crates including builtin types

1 files changed, 40 insertions, 13 deletions

diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index eb1cd66fb..a9d3c9156 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -696,8 +696,8 @@ impl Adt {
         }
     }
 
-    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
-        Some(self.module(db).krate())
+    pub fn krate(self, db: &dyn HirDatabase) -> Crate {
+        self.module(db).krate()
     }
 
     pub fn name(self, db: &dyn HirDatabase) -> Name {
@@ -1019,8 +1019,8 @@ impl TypeAlias {
         Module { id: self.id.lookup(db.upcast()).module(db.upcast()) }
     }
 
-    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
-        Some(self.module(db).krate())
+    pub fn krate(self, db: &dyn HirDatabase) -> Crate {
+        self.module(db).krate()
     }
 
     pub fn type_ref(self, db: &dyn HirDatabase) -> Option<TypeRef> {
@@ -1483,9 +1483,42 @@ impl Impl {
 
         inherent.all_impls().chain(trait_.all_impls()).map(Self::from).collect()
     }
-    pub fn for_trait(db: &dyn HirDatabase, krate: Crate, trait_: Trait) -> Vec<Impl> {
-        let impls = db.trait_impls_in_crate(krate.id);
-        impls.for_trait(trait_.id).map(Self::from).collect()
+
+    pub fn all_for_type(db: &dyn HirDatabase, Type { krate, ty }: Type) -> Vec<Impl> {
+        let def_crates = match ty.value.def_crates(db, krate) {
+            Some(def_crates) => def_crates,
+            None => return vec![],
+        };
+
+        let filter = |impl_def: &Impl| {
+            let target_ty = impl_def.target_ty(db);
+            let rref = target_ty.remove_ref();
+            ty.value.equals_ctor(rref.as_ref().map_or(&target_ty.ty.value, |it| &it.ty.value))
+        };
+
+        let mut all = Vec::new();
+        def_crates.iter().for_each(|&id| {
+            all.extend(db.inherent_impls_in_crate(id).all_impls().map(Self::from).filter(filter))
+        });
+        for id in def_crates
+            .iter()
+            .flat_map(|&id| Crate { id }.reverse_dependencies(db))
+            .map(|Crate { id }| id)
+            .chain(def_crates.iter().copied())
+        {
+            all.extend(db.trait_impls_in_crate(id).all_impls().map(Self::from).filter(filter));
+        }
+        all
+    }
+
+    pub fn all_for_trait(db: &dyn HirDatabase, trait_: Trait) -> Vec<Impl> {
+        let krate = trait_.module(db).krate();
+        let mut all = Vec::new();
+        for Crate { id } in krate.reverse_dependencies(db).into_iter().chain(Some(krate)) {
+            let impls = db.trait_impls_in_crate(id);
+            all.extend(impls.for_trait(trait_.id).map(Self::from))
+        }
+        all
     }
 
     // FIXME: the return type is wrong. This should be a hir version of
@@ -1913,12 +1946,6 @@ impl Type {
         self.ty.value.associated_type_parent_trait(db).map(Into::into)
     }
 
-    // FIXME: provide required accessors such that it becomes implementable from outside.
-    pub fn is_equal_for_find_impls(&self, other: &Type) -> bool {
-        let rref = other.remove_ref();
-        self.ty.value.equals_ctor(rref.as_ref().map_or(&other.ty.value, |it| &it.ty.value))
-    }
-
     fn derived(&self, ty: Ty) -> Type {
         Type {
             krate: self.krate,