Add AST definitions for struct/variant fields etc.

Fixes #117

1 files changed, 31 insertions, 0 deletions

diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index f12479fb4..5dbf9b221 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -363,3 +363,34 @@ impl<'a, N: AstNode<'a>> Iterator for AstChildren<'a, N> {
         }
     }
 }
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum StructFlavor<'a> {
+    Tuple(PosFieldList<'a>),
+    Named(NamedFieldDefList<'a>),
+    Unit,
+}
+
+impl<'a> StructFlavor<'a> {
+    fn from_node<N: AstNode<'a>>(node: N) -> StructFlavor<'a> {
+        if let Some(nfdl) = child_opt::<_, NamedFieldDefList>(node) {
+            StructFlavor::Named(nfdl)
+        } else if let Some(pfl) = child_opt::<_, PosFieldList>(node) {
+            StructFlavor::Tuple(pfl)
+        } else {
+            StructFlavor::Unit
+        }
+    }
+}
+
+impl<'a> StructDef<'a> {
+    pub fn flavor(self) -> StructFlavor<'a> {
+        StructFlavor::from_node(self)
+    }
+}
+
+impl<'a> EnumVariant<'a> {
+    pub fn flavor(self) -> StructFlavor<'a> {
+        StructFlavor::from_node(self)
+    }
+}