Allow iterating fields in the ItemTree

crates/ra_hir_def/src/item_tree.rs

@@ -681,10 +681,28 @@ pub struct Variant {
     pub fields: Fields,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct FieldIds {
+    range: Range<u32>,
+}
+
+impl FieldIds {
+    fn new(range: Range<Idx<Field>>) -> Self {
+        Self { range: range.start.into_raw().into()..range.end.into_raw().into() }
+    }
+}
+
+impl Iterator for FieldIds {
+    type Item = Idx<Field>;
+    fn next(&mut self) -> Option<Self::Item> {
+        self.range.next().map(|raw| Idx::from_raw(raw.into()))
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Fields {
-    Record(Range<Idx<Field>>),
+    Record(FieldIds),
-    Tuple(Range<Idx<Field>>),
+    Tuple(FieldIds),
     Unit,
 }
 

crates/ra_hir_def/src/item_tree/lower.rs

@@ -196,7 +196,7 @@ impl Ctx {
         }
     }
 
-    fn lower_record_fields(&mut self, fields: &ast::RecordFieldDefList) -> Range<Idx<Field>> {
+    fn lower_record_fields(&mut self, fields: &ast::RecordFieldDefList) -> FieldIds {
         let start = self.next_field_idx();
         for field in fields.fields() {
             if let Some(data) = self.lower_record_field(&field) {
@@ -204,7 +204,7 @@ impl Ctx {
             }
         }
         let end = self.next_field_idx();
-        start..end
+        FieldIds::new(start..end)
     }
 
     fn lower_record_field(&mut self, field: &ast::RecordFieldDef) -> Option<Field> {
@@ -215,7 +215,7 @@ impl Ctx {
         Some(res)
     }
 
-    fn lower_tuple_fields(&mut self, fields: &ast::TupleFieldDefList) -> Range<Idx<Field>> {
+    fn lower_tuple_fields(&mut self, fields: &ast::TupleFieldDefList) -> FieldIds {
         let start = self.next_field_idx();
         for (i, field) in fields.fields().enumerate() {
             if let Some(data) = self.lower_tuple_field(i, &field) {
@@ -223,7 +223,7 @@ impl Ctx {
             }
         }
         let end = self.next_field_idx();
-        start..end
+        FieldIds::new(start..end)
     }
 
     fn lower_tuple_field(&mut self, idx: usize, field: &ast::TupleFieldDef) -> Option<Field> {
@@ -242,7 +242,7 @@ impl Ctx {
             Some(record_field_def_list) => {
                 self.lower_fields(&StructKind::Record(record_field_def_list))
             }
-            None => Fields::Record(self.next_field_idx()..self.next_field_idx()),
+            None => Fields::Record(FieldIds::new(self.next_field_idx()..self.next_field_idx())),
         };
         let ast_id = self.source_ast_id_map.ast_id(union);
         let res = Union { name, visibility, generic_params, fields, ast_id };

crates/ra_hir_def/src/item_tree/tests.rs

@@ -237,13 +237,13 @@ Trait { name: Name(Text("Tr")), visibility: RawVisibilityId("pub(self)"), generi
 #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("struct0"))] }, input: None }]) }]
 Struct { name: Name(Text("Struct0")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(1), fields: Unit, ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(3), kind: Unit }
 #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("struct1"))] }, input: None }]) }]
-Struct { name: Name(Text("Struct1")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(2), fields: Tuple(Idx::<Field>(0)..Idx::<Field>(1)), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(4), kind: Tuple }
+Struct { name: Name(Text("Struct1")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(2), fields: Tuple(FieldIds { range: 0..1 }), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(4), kind: Tuple }
 #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("struct2"))] }, input: None }]) }]
-Struct { name: Name(Text("Struct2")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(3), fields: Record(Idx::<Field>(1)..Idx::<Field>(2)), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(5), kind: Record }
+Struct { name: Name(Text("Struct2")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(3), fields: Record(FieldIds { range: 1..2 }), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(5), kind: Record }
 #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("en"))] }, input: None }]) }]
 Enum { name: Name(Text("En")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), variants: Idx::<Variant>(0)..Idx::<Variant>(1), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::EnumDef>(6) }
 #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("un"))] }, input: None }]) }]
-Union { name: Name(Text("Un")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), fields: Record(Idx::<Field>(3)..Idx::<Field>(4)), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::UnionDef>(7) }
+Union { name: Name(Text("Un")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), fields: Record(FieldIds { range: 3..4 }), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::UnionDef>(7) }
     "###);
 }