src/Pure/System/invoke_scala.ML

--- a/src/Pure/System/invoke_scala.ML	Fri Aug 19 13:55:32 2011 +0200
+++ b/src/Pure/System/invoke_scala.ML	Fri Aug 19 14:01:20 2011 +0200
@@ -33,7 +33,8 @@
 fun promise_method name arg =
   let
     val id = new_id ();
-    val promise = Future.promise () : string future;
+    fun abort () = Output.raw_message (Markup.cancel_scala id) "";
+    val promise = Future.promise abort : string future;
     val _ = Synchronized.change promises (Symtab.update (id, promise));
     val _ = Output.raw_message (Markup.invoke_scala name id) arg;
   in promise end;