1 files changed, 37 insertions, 64 deletions

diff --git a/crates/ide_db/src/helpers/import_assets.rs b/crates/ide_db/src/helpers/import_assets.rs
index 0da4bdd0e..66e60b698 100644
--- a/crates/ide_db/src/helpers/import_assets.rs
+++ b/crates/ide_db/src/helpers/import_assets.rs
@@ -183,39 +183,41 @@ impl ImportAssets {
     }
 
     fn applicable_defs<'a>(
-        &self,
+        &'a self,
         sema: &'a Semantics<RootDatabase>,
         prefixed: Option<hir::PrefixKind>,
-        unfiltered_imports: Box<dyn Iterator<Item = Either<ModuleDef, MacroDef>> + 'a>,
+        unfiltered_defs: impl Iterator<Item = Either<ModuleDef, MacroDef>> + 'a,
     ) -> Box<dyn Iterator<Item = (ModPath, ItemInNs)> + 'a> {
         let current_crate = self.module_with_candidate.krate();
         let db = sema.db;
 
         match &self.import_candidate {
-            ImportCandidate::Path(path_candidate) => path_applicable_defs(
+            ImportCandidate::Path(path_candidate) => Box::new(path_applicable_defs(
                 sema,
                 path_candidate,
-                unfiltered_imports,
-                self.module_with_candidate,
-                prefixed,
-            ),
-            ImportCandidate::TraitAssocItem(trait_candidate) => trait_applicable_defs(
-                db,
-                current_crate,
-                trait_candidate,
-                true,
-                unfiltered_imports,
-                self.module_with_candidate,
-                prefixed,
+                unfiltered_defs
+                    .into_iter()
+                    .map(|def| def.either(ItemInNs::from, ItemInNs::from))
+                    .filter_map(move |item_to_search| {
+                        get_mod_path(db, item_to_search, &self.module_with_candidate, prefixed)
+                            .zip(Some(item_to_search))
+                    }),
+            )),
+            ImportCandidate::TraitAssocItem(trait_candidate) => Box::new(
+                trait_applicable_defs(db, current_crate, trait_candidate, true, unfiltered_defs)
+                    .into_iter()
+                    .filter_map(move |item_to_search| {
+                        get_mod_path(db, item_to_search, &self.module_with_candidate, prefixed)
+                            .zip(Some(item_to_search))
+                    }),
             ),
-            ImportCandidate::TraitMethod(trait_candidate) => trait_applicable_defs(
-                db,
-                current_crate,
-                trait_candidate,
-                false,
-                unfiltered_imports,
-                self.module_with_candidate,
-                prefixed,
+            ImportCandidate::TraitMethod(trait_candidate) => Box::new(
+                trait_applicable_defs(db, current_crate, trait_candidate, false, unfiltered_defs)
+                    .into_iter()
+                    .filter_map(move |item_to_search| {
+                        get_mod_path(db, item_to_search, &self.module_with_candidate, prefixed)
+                            .zip(Some(item_to_search))
+                    }),
             ),
         }
     }
@@ -224,22 +226,12 @@ impl ImportAssets {
 fn path_applicable_defs<'a>(
     sema: &'a Semantics<RootDatabase>,
     path_candidate: &PathImportCandidate,
-    unfiltered_defs: Box<dyn Iterator<Item = Either<ModuleDef, MacroDef>> + 'a>,
-    module_with_candidate: Module,
-    prefixed: Option<hir::PrefixKind>,
-) -> Box<dyn Iterator<Item = (ModPath, ItemInNs)> + 'a> {
-    let applicable_defs = unfiltered_defs
-        .map(|candidate| candidate.either(ItemInNs::from, ItemInNs::from))
-        .filter_map(move |item_to_search| {
-            get_mod_path(sema.db, item_to_search, &module_with_candidate, prefixed)
-                .zip(Some(item_to_search))
-        });
-
+    unfiltered_defs: impl Iterator<Item = (ModPath, ItemInNs)> + 'a,
+) -> impl Iterator<Item = (ModPath, ItemInNs)> + 'a {
     let unresolved_qualifier = match &path_candidate.unresolved_qualifier {
         Some(qualifier) => qualifier,
         None => {
-            // TODO kb too many boxes tossed around
-            return Box::new(applicable_defs);
+            return unfiltered_defs;
         }
     };
 
@@ -252,7 +244,7 @@ fn path_applicable_defs<'a>(
         // first segment is already unresolved, need to turn it into ModuleDef somehow
     }
 
-    return Box::new(applicable_defs);
+    return unfiltered_defs;
 }
 
 fn resolve_qualifier_start(
@@ -269,10 +261,8 @@ fn trait_applicable_defs<'a>(
     current_crate: Crate,
     trait_candidate: &TraitImportCandidate,
     trait_assoc_item: bool,
-    unfiltered_defs: Box<dyn Iterator<Item = Either<ModuleDef, MacroDef>> + 'a>,
-    module_with_candidate: Module,
-    prefixed: Option<hir::PrefixKind>,
-) -> Box<dyn Iterator<Item = (ModPath, ItemInNs)> + 'a> {
+    unfiltered_defs: impl Iterator<Item = Either<ModuleDef, MacroDef>> + 'a,
+) -> FxHashSet<ItemInNs> {
     let mut required_assoc_items = FxHashSet::default();
 
     let trait_candidates = unfiltered_defs
@@ -287,7 +277,7 @@ fn trait_applicable_defs<'a>(
         })
         .collect();
 
-    let mut applicable_defs = FxHashSet::default();
+    let mut applicable_traits = FxHashSet::default();
 
     if trait_assoc_item {
         trait_candidate.receiver_ty.iterate_path_candidates(
@@ -302,7 +292,8 @@ fn trait_applicable_defs<'a>(
                             return None;
                         }
                     }
-                    applicable_defs.insert(assoc_to_module_def(assoc));
+                    applicable_traits
+                        .insert(ItemInNs::from(ModuleDef::from(assoc.containing_trait(db)?)));
                 }
                 None::<()>
             },
@@ -316,25 +307,15 @@ fn trait_applicable_defs<'a>(
             |_, function| {
                 let assoc = function.as_assoc_item(db)?;
                 if required_assoc_items.contains(&assoc) {
-                    applicable_defs.insert(assoc_to_module_def(assoc));
+                    applicable_traits
+                        .insert(ItemInNs::from(ModuleDef::from(assoc.containing_trait(db)?)));
                 }
                 None::<()>
             },
         )
     };
 
-    Box::new(
-        applicable_defs
-            .into_iter()
-            .filter_map(move |candidate| {
-                let canidate_trait = candidate.as_assoc_item(db)?.containing_trait(db)?;
-                Some(ItemInNs::from(ModuleDef::from(canidate_trait)))
-            })
-            .filter_map(move |item_to_search| {
-                get_mod_path(db, item_to_search, &module_with_candidate, prefixed)
-                    .zip(Some(item_to_search))
-            }),
-    )
+    applicable_traits
 }
 
 fn get_mod_path(
@@ -350,14 +331,6 @@ fn get_mod_path(
     }
 }
 
-fn assoc_to_module_def(assoc: AssocItem) -> ModuleDef {
-    match assoc {
-        AssocItem::Function(f) => f.into(),
-        AssocItem::Const(c) => c.into(),
-        AssocItem::TypeAlias(t) => t.into(),
-    }
-}
-
 impl ImportCandidate {
     fn for_method_call(
         sema: &Semantics<RootDatabase>,