1 files changed, 2 insertions, 1 deletions
diff --git a/Syntax.sml b/Syntax.sml
index 0d10dd2..c9e4323 100644
--- a/Syntax.sml
+++ b/Syntax.sml
@@ -36,7 +36,8 @@ struct
   | DFun of string * (pat list * expr) list
   | DDatatype of string list * string * (string * etype option) list
   | DType of string * etype
-  | DStruct of string * structExpr
+  | DStruct of string * string option * structExpr
+  | DSig of string * (string * etype) list
 
   and structExpr =
     SIdent of string