diff -r 000000000000 -r 9753524d698f launcher/fx/src/main/java/org/apidesign/bck2brwsr/launcher/fximpl/Fn.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/launcher/fx/src/main/java/org/apidesign/bck2brwsr/launcher/fximpl/Fn.java	Mon Jun 10 18:19:40 2013 +0200
@@ -0,0 +1,32 @@
+/**
+ * Back 2 Browser Bytecode Translator
+ * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. Look for COPYING file in the top folder.
+ * If not, see http://opensource.org/licenses/GPL-2.0.
+ */
+package org.apidesign.bck2brwsr.launcher.fximpl;
+
+/**
+ *
+ * @author Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ */
+public abstract class Fn {
+    public static Fn define(Class<?> caller, String code, String... names) {
+        JsClassLoader cl = (JsClassLoader)caller.getClassLoader();
+        return cl.defineFn(code, names);
+    }
+
+    public abstract Object invoke(Object... args) throws Exception;
+    
+}