added multiple trait inheritance.

- a class can now extend more than one traits

1 files changed, 7 insertions, 3 deletions

diff --git a/Source/Dafny/Dafny.atg b/Source/Dafny/Dafny.atg
index b59c586a..137c6215 100644
--- a/Source/Dafny/Dafny.atg
+++ b/Source/Dafny/Dafny.atg
@@ -447,7 +447,8 @@ ClassDecl<ModuleDefinition/*!*/ module, out ClassDecl/*!*/ c>
 = (. Contract.Requires(module != null);

      Contract.Ensures(Contract.ValueAtReturn(out c) != null);

      IToken/*!*/ id;

-     Type/*!*/ trait = null;

+	 Type trait = null;

+     List<Type>/*!*/ traits = new List<Type>();

 	 Attributes attrs = null;

      List<TypeParameter/*!*/> typeArgs = new List<TypeParameter/*!*/>();

      List<MemberDecl/*!*/> members = new List<MemberDecl/*!*/>();

@@ -458,12 +459,15 @@ ClassDecl<ModuleDefinition/*!*/ module, out ClassDecl/*!*/ c>
   { Attribute<ref attrs> }

   NoUSIdent<out id>

   [ GenericParameters<typeArgs> ]

-  ["extends" Type<out trait>]         

+  ["extends" 

+  Type<out trait>		(. traits.Add(trait); .) 

+  {"," Type<out trait>  (. traits.Add(trait); .) }

+  ]         

   "{"                                            (. bodyStart = t;  .)

   { ClassMemberDecl<members, true>

   }

   "}"

-  (. c = new ClassDecl(id, id.val, module, typeArgs, members, attrs, trait);

+  (. c = new ClassDecl(id, id.val, module, typeArgs, members, attrs, traits);

      c.BodyStartTok = bodyStart;

      c.BodyEndTok = t;

   .)