6 files changed, 79 insertions, 30 deletions
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 0f9ff97f1..f7efc1b66 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -510,18 +510,6 @@ pub enum DefWithBody {
 impl_froms!(DefWithBody: Function, Const, Static);
 impl DefWithBody {
-    pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
-        db.infer(self)
-    }
-    pub fn body(self, db: &impl HirDatabase) -> Arc<Body> {
-        db.body_hir(self)
-    }
-    pub fn body_source_map(self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
-        db.body_with_source_map(self).1
-    }
    /// Builds a resolver for code inside this item.
    pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
        match self {
@@ -532,6 +520,43 @@ impl DefWithBody {
    }
 }
+pub trait HasBody: Copy {
+    fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult>;
+    fn body(self, db: &impl HirDatabase) -> Arc<Body>;
+    fn body_source_map(self, db: &impl HirDatabase) -> Arc<BodySourceMap>;
+}
+impl<T> HasBody for T
+where
+    T: Into<DefWithBody> + Copy + HasSource,
+{
+    fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
+        db.infer(self.into())
+    }
+    fn body(self, db: &impl HirDatabase) -> Arc<Body> {
+        db.body_hir(self.into())
+    }
+    fn body_source_map(self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
+        db.body_with_source_map(self.into()).1
+    }
+}
+impl HasBody for DefWithBody {
+    fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
+        db.infer(self)
+    }
+    fn body(self, db: &impl HirDatabase) -> Arc<Body> {
+        db.body_hir(self)
+    }
+    fn body_source_map(self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
+        db.body_with_source_map(self).1
+    }
+}
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Function {
    pub(crate) id: FunctionId,
@@ -617,7 +642,7 @@ impl Function {
        self.data(db).name.clone()
    }
-    pub fn body_source_map(self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
+    pub(crate) fn body_source_map(self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
        db.body_with_source_map(self.into()).1
    }
diff --git a/crates/ra_hir/src/code_model/src.rs b/crates/ra_hir/src/code_model/src.rs
index 32bd9c661..e5bae16ab 100644
--- a/crates/ra_hir/src/code_model/src.rs
+++ b/crates/ra_hir/src/code_model/src.rs
@@ -1,9 +1,9 @@
-use ra_syntax::ast;
+use ra_syntax::ast::{self, AstNode};
 use crate::{
    ids::AstItemDef, AstDatabase, Const, DefDatabase, Enum, EnumVariant, FieldSource, Function,
-    HirFileId, MacroDef, Module, ModuleSource, Static, Struct, StructField, Trait, TypeAlias,
+    HasBody, HirDatabase, HirFileId, MacroDef, Module, ModuleSource, Static, Struct, StructField,
-    Union,
+    Trait, TypeAlias, Union,
 };
 pub struct Source<T> {
@@ -108,3 +108,27 @@ impl HasSource for MacroDef {
        Source { file_id: self.id.0.file_id(), ast: self.id.0.to_node(db) }
    }
 }
+pub trait HasBodySource: HasBody + HasSource
+where
+    Self::Ast: AstNode,
+{
+    fn expr_source(
+        self,
+        db: &impl HirDatabase,
+        expr_id: crate::expr::ExprId,
+    ) -> Option<Source<ast::Expr>> {
+        let source_map = self.body_source_map(db);
+        let expr_syntax = source_map.expr_syntax(expr_id)?;
+        let source = self.source(db);
+        let node = expr_syntax.to_node(&source.ast.syntax());
+        ast::Expr::cast(node).map(|ast| Source { file_id: source.file_id, ast })
+    }
+}
+impl<T> HasBodySource for T
+where
+    T: HasBody + HasSource,
+    T::Ast: AstNode,
+{
+}
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index 57225ae91..7cdc7555c 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -128,27 +128,27 @@ impl Index<PatId> for Body {
 }
 impl BodySourceMap {
-    pub fn expr_syntax(&self, expr: ExprId) -> Option<SyntaxNodePtr> {
+    pub(crate) fn expr_syntax(&self, expr: ExprId) -> Option<SyntaxNodePtr> {
        self.expr_map_back.get(expr).cloned()
    }
-    pub fn syntax_expr(&self, ptr: SyntaxNodePtr) -> Option<ExprId> {
+    pub(crate) fn syntax_expr(&self, ptr: SyntaxNodePtr) -> Option<ExprId> {
        self.expr_map.get(&ptr).cloned()
    }
-    pub fn node_expr(&self, node: &ast::Expr) -> Option<ExprId> {
+    pub(crate) fn node_expr(&self, node: &ast::Expr) -> Option<ExprId> {
        self.expr_map.get(&SyntaxNodePtr::new(node.syntax())).cloned()
    }
-    pub fn pat_syntax(&self, pat: PatId) -> Option<PatPtr> {
+    pub(crate) fn pat_syntax(&self, pat: PatId) -> Option<PatPtr> {
        self.pat_map_back.get(pat).cloned()
    }
-    pub fn node_pat(&self, node: &ast::Pat) -> Option<PatId> {
+    pub(crate) fn node_pat(&self, node: &ast::Pat) -> Option<PatId> {
        self.pat_map.get(&Either::A(AstPtr::new(node))).cloned()
    }
-    pub fn field_syntax(&self, expr: ExprId, field: usize) -> AstPtr<ast::RecordField> {
+    pub(crate) fn field_syntax(&self, expr: ExprId, field: usize) -> AstPtr<ast::RecordField> {
        self.field_map[&(expr, field)]
    }
 }
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 018fcd096..752653ad7 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -75,8 +75,8 @@ pub use self::{
 pub use self::code_model::{
    docs::{DocDef, Docs, Documentation},
-    src::{HasSource, Source},
+    src::{HasBodySource, HasSource, Source},
    BuiltinType, Const, ConstData, Container, Crate, CrateDependency, DefWithBody, Enum,
-    EnumVariant, FieldSource, FnData, Function, MacroDef, Module, ModuleDef, ModuleSource, Static,
+    EnumVariant, FieldSource, FnData, Function, HasBody, MacroDef, Module, ModuleDef, ModuleSource,
-    Struct, StructField, Trait, TypeAlias, Union,
+    Static, Struct, StructField, Trait, TypeAlias, Union,
 };
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index 56ff7da3a..43aec201a 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -27,9 +27,9 @@ use crate::{
    name,
    path::{PathKind, PathSegment},
    ty::method_resolution::implements_trait,
-    AsName, AstId, Const, Crate, DefWithBody, Either, Enum, Function, HirDatabase, HirFileId,
+    AsName, AstId, Const, Crate, DefWithBody, Either, Enum, Function, HasBody, HirDatabase,
-    MacroDef, Module, ModuleDef, Name, Path, PerNs, Resolution, Resolver, Static, Struct, Trait,
+    HirFileId, MacroDef, Module, ModuleDef, Name, Path, PerNs, Resolution, Resolver, Static,
-    Ty,
+    Struct, Trait, Ty,
 };
 /// Locates the module by `FileId`. Picks topmost module in the file.
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index 812990426..9ba146299 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -50,8 +50,8 @@ use crate::{
    },
    ty::infer::diagnostics::InferenceDiagnostic,
    type_ref::{Mutability, TypeRef},
-    AdtDef, ConstData, DefWithBody, FnData, Function, HirDatabase, ImplItem, ModuleDef, Name, Path,
+    AdtDef, ConstData, DefWithBody, FnData, Function, HasBody, HirDatabase, ImplItem, ModuleDef,
-    StructField,
+    Name, Path, StructField,
 };
 mod unify;