3 files changed, 81 insertions, 76 deletions

diff --git a/crates/ra_hir/src/from_id.rs b/crates/ra_hir/src/from_id.rs
index c16c17072..3aa7c4870 100644
--- a/crates/ra_hir/src/from_id.rs
+++ b/crates/ra_hir/src/from_id.rs
@@ -40,6 +40,7 @@ from_id![
     (hir_def::ConstId, crate::Const),
     (hir_def::FunctionId, crate::Function),
     (hir_def::ImplId, crate::ImplBlock),
+    (hir_def::TypeParamId, crate::TypeParam),
     (hir_expand::MacroDefId, crate::MacroDef)
 ];
 
diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 22a7e7588..9fedb7657 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -4,16 +4,16 @@ use std::{cell::RefCell, fmt, iter::successors};
 
 use hir_def::{
     resolver::{self, HasResolver, Resolver},
-    TraitId,
+    DefWithBodyId, TraitId,
 };
 use ra_db::{FileId, FileRange};
-use ra_syntax::{ast, AstNode, SyntaxNode, SyntaxToken, TextRange, TextUnit};
+use ra_syntax::{ast, match_ast, AstNode, SyntaxNode, SyntaxToken, TextRange, TextUnit};
 use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{
     db::HirDatabase,
     source_analyzer::{resolve_hir_path, ReferenceDescriptor, SourceAnalyzer},
-    source_binder::{ChildContainer, SourceBinder, ToDef},
+    source_binder::{ChildContainer, SourceBinder},
     Function, HirFileId, InFile, Local, MacroDef, Module, Name, Origin, Path, PathResolution,
     ScopeDef, StructField, Trait, Type, TypeParam, VariantDef,
 };
@@ -129,9 +129,7 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
     // pub fn resolve_name_ref(&self, name_ref: &ast::NameRef) -> Option<???>;
 
     pub fn to_def<T: ToDef + Clone>(&self, src: &T) -> Option<T::Def> {
-        let src = self.find_file(src.syntax().clone()).with_value(src.clone());
-        let mut sb = self.sb.borrow_mut();
-        T::to_def(self.db, &mut sb, src)
+        T::to_def(self, src)
     }
 
     pub fn to_module_def(&self, file: FileId) -> Option<Module> {
@@ -227,6 +225,68 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
     }
 }
 
+pub trait ToDef: Sized + AstNode + 'static {
+    type Def;
+    fn to_def<DB: HirDatabase>(sema: &Semantics<DB>, src: &Self) -> Option<Self::Def>;
+}
+
+macro_rules! to_def_impls {
+    ($(($def:path, $ast:path)),* ,) => {$(
+        impl ToDef for $ast {
+            type Def = $def;
+            fn to_def<DB: HirDatabase>(sema: &Semantics<DB>, src: &Self)
+                -> Option<Self::Def>
+            {
+                let src = sema.find_file(src.syntax().clone()).with_value(src);
+                sema.sb.borrow_mut().to_id(sema.db, src.cloned()).map(Into::into)
+            }
+        }
+    )*}
+}
+
+to_def_impls![
+    (crate::Module, ast::Module),
+    (crate::Struct, ast::StructDef),
+    (crate::Enum, ast::EnumDef),
+    (crate::Union, ast::UnionDef),
+    (crate::Trait, ast::TraitDef),
+    (crate::ImplBlock, ast::ImplBlock),
+    (crate::TypeAlias, ast::TypeAliasDef),
+    (crate::Const, ast::ConstDef),
+    (crate::Static, ast::StaticDef),
+    (crate::Function, ast::FnDef),
+    (crate::StructField, ast::RecordFieldDef),
+    (crate::EnumVariant, ast::EnumVariant),
+    (crate::TypeParam, ast::TypeParam),
+    (crate::MacroDef, ast::MacroCall), // this one is dubious, not all calls are macros
+];
+
+impl ToDef for ast::BindPat {
+    type Def = Local;
+
+    fn to_def<DB: HirDatabase>(sema: &Semantics<DB>, src: &Self) -> Option<Local> {
+        let src = sema.find_file(src.syntax().clone()).with_value(src);
+        let file_id = src.file_id;
+        let mut sb = sema.sb.borrow_mut();
+        let db = sema.db;
+        let parent: DefWithBodyId = src.value.syntax().ancestors().find_map(|it| {
+            let res = match_ast! {
+                match it {
+                    ast::ConstDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
+                    ast::StaticDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
+                    ast::FnDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
+                    _ => return None,
+                }
+            };
+            Some(res)
+        })?;
+        let (_body, source_map) = db.body_with_source_map(parent);
+        let src = src.cloned().map(ast::Pat::from);
+        let pat_id = source_map.node_pat(src.as_ref())?;
+        Some(Local { parent: parent.into(), pat_id })
+    }
+}
+
 fn find_root(node: &SyntaxNode) -> SyntaxNode {
     node.ancestors().last().unwrap()
 }
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index 0b8a641f9..4353e25ac 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -6,7 +6,7 @@ use hir_def::{
     dyn_map::DynMap,
     keys::{self, Key},
     ConstId, DefWithBodyId, EnumId, EnumVariantId, FunctionId, GenericDefId, ImplId, ModuleId,
-    StaticId, StructFieldId, StructId, TraitId, TypeAliasId, UnionId, VariantId,
+    StaticId, StructFieldId, StructId, TraitId, TypeAliasId, TypeParamId, UnionId, VariantId,
 };
 use hir_expand::{name::AsName, AstId, InFile, MacroDefId, MacroDefKind};
 use ra_db::FileId;
@@ -17,9 +17,9 @@ use ra_syntax::{
 };
 use rustc_hash::FxHashMap;
 
-use crate::{db::HirDatabase, Local, Module, TypeParam};
+use crate::{db::HirDatabase, Module};
 
-pub struct SourceBinder {
+pub(crate) struct SourceBinder {
     child_by_source_cache: FxHashMap<ChildContainer, DynMap>,
 }
 
@@ -38,7 +38,11 @@ impl SourceBinder {
         Some(Module { id: ModuleId { krate, local_id } })
     }
 
-    fn to_id<T: ToId>(&mut self, db: &impl HirDatabase, src: InFile<T>) -> Option<T::ID> {
+    pub(crate) fn to_id<T: ToId>(
+        &mut self,
+        db: &impl HirDatabase,
+        src: InFile<T>,
+    ) -> Option<T::ID> {
         T::to_id(db, self, src)
     }
 
@@ -118,42 +122,6 @@ pub(crate) trait ToId: Sized {
     ) -> Option<Self::ID>;
 }
 
-pub trait ToDef: Sized + AstNode + 'static {
-    type Def;
-    fn to_def<DB: HirDatabase>(
-        db: &DB,
-        sb: &mut SourceBinder,
-        src: InFile<Self>,
-    ) -> Option<Self::Def>;
-}
-
-macro_rules! to_def_impls {
-    ($(($def:path, $ast:path)),* ,) => {$(
-        impl ToDef for $ast {
-            type Def = $def;
-            fn to_def<DB: HirDatabase>(db: &DB, sb: &mut SourceBinder, src: InFile<Self>)
-                -> Option<Self::Def>
-            { sb.to_id(db, src).map(Into::into) }
-        }
-    )*}
-}
-
-to_def_impls![
-    (crate::Module, ast::Module),
-    (crate::Struct, ast::StructDef),
-    (crate::Enum, ast::EnumDef),
-    (crate::Union, ast::UnionDef),
-    (crate::Trait, ast::TraitDef),
-    (crate::ImplBlock, ast::ImplBlock),
-    (crate::TypeAlias, ast::TypeAliasDef),
-    (crate::Const, ast::ConstDef),
-    (crate::Static, ast::StaticDef),
-    (crate::Function, ast::FnDef),
-    (crate::StructField, ast::RecordFieldDef),
-    (crate::EnumVariant, ast::EnumVariant),
-    (crate::MacroDef, ast::MacroCall), // this one is dubious, not all calls are macros
-];
-
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
 pub(crate) enum ChildContainer {
     DefWithBodyId(DefWithBodyId),
@@ -245,37 +213,14 @@ impl ToId for ast::MacroCall {
     }
 }
 
-impl ToDef for ast::BindPat {
-    type Def = Local;
+impl ToId for ast::TypeParam {
+    type ID = TypeParamId;
 
-    fn to_def<DB: HirDatabase>(db: &DB, sb: &mut SourceBinder, src: InFile<Self>) -> Option<Local> {
-        let file_id = src.file_id;
-        let parent: DefWithBodyId = src.value.syntax().ancestors().find_map(|it| {
-            let res = match_ast! {
-                match it {
-                    ast::ConstDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
-                    ast::StaticDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
-                    ast::FnDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
-                    _ => return None,
-                }
-            };
-            Some(res)
-        })?;
-        let (_body, source_map) = db.body_with_source_map(parent);
-        let src = src.map(ast::Pat::from);
-        let pat_id = source_map.node_pat(src.as_ref())?;
-        Some(Local { parent: parent.into(), pat_id })
-    }
-}
-
-impl ToDef for ast::TypeParam {
-    type Def = TypeParam;
-
-    fn to_def<DB: HirDatabase>(
+    fn to_id<DB: HirDatabase>(
         db: &DB,
         sb: &mut SourceBinder,
-        src: InFile<ast::TypeParam>,
-    ) -> Option<TypeParam> {
+        src: InFile<Self>,
+    ) -> Option<Self::ID> {
         let file_id = src.file_id;
         let parent: GenericDefId = src.value.syntax().ancestors().find_map(|it| {
             let res = match_ast! {
@@ -291,8 +236,7 @@ impl ToDef for ast::TypeParam {
             };
             Some(res)
         })?;
-        let &id = sb.child_by_source(db, parent.into())[keys::TYPE_PARAM].get(&src)?;
-        Some(TypeParam { id })
+        sb.child_by_source(db, parent.into())[keys::TYPE_PARAM].get(&src).copied()
     }
 }