src/Pure/System/invoke_scala.ML

--- a/src/Pure/System/invoke_scala.ML	Sun Mar 30 21:24:59 2014 +0200
+++ b/src/Pure/System/invoke_scala.ML	Mon Mar 31 10:28:08 2014 +0200
@@ -30,10 +30,10 @@
 fun promise_method name arg =
   let
     val id = new_id ();
-    fun abort () = Output.protocol_message (Markup.cancel_scala id) "";
+    fun abort () = Output.protocol_message (Markup.cancel_scala id) [];
     val promise = Future.promise abort : string future;
     val _ = Synchronized.change promises (Symtab.update (id, promise));
-    val _ = Output.protocol_message (Markup.invoke_scala name id) arg;
+    val _ = Output.protocol_message (Markup.invoke_scala name id) [arg];
   in promise end;
 
 fun method name arg = Future.join (promise_method name arg);