diff -r cde0c2d7794e -r 2569d9dd4b28 emul/mini/src/main/java/org/apidesign/bck2brwsr/emul/reflect/MethodImpl.java
--- a/emul/mini/src/main/java/org/apidesign/bck2brwsr/emul/reflect/MethodImpl.java	Wed Jan 23 20:52:11 2013 +0100
+++ b/emul/mini/src/main/java/org/apidesign/bck2brwsr/emul/reflect/MethodImpl.java	Sun Feb 03 11:01:08 2013 +0100
@@ -24,6 +24,7 @@
  */
 package org.apidesign.bck2brwsr.emul.reflect;
 
+import java.lang.reflect.Array;
 import java.lang.reflect.Method;
 import java.util.Enumeration;
 import org.apidesign.bck2brwsr.core.JavaScriptBody;
@@ -41,7 +42,7 @@
             throw new IllegalStateException(ex);
         }
     }
-    
+
     protected abstract Method create(Class<?> declaringClass, String name, Object data, String sig);
     
     
@@ -107,6 +108,62 @@
         }
         return arr;
     }
+    static String toSignature(Method m) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(m.getName()).append("__");
+        appendType(sb, m.getReturnType());
+        Class<?>[] arr = m.getParameterTypes();
+        for (int i = 0; i < arr.length; i++) {
+            appendType(sb, arr[i]);
+        }
+        return sb.toString();
+    }
+    
+    private static void appendType(StringBuilder sb, Class<?> type) {
+        if (type == Integer.TYPE) {
+            sb.append('I');
+            return;
+        }
+        if (type == Long.TYPE) {
+            sb.append('J');
+            return;
+        }
+        if (type == Double.TYPE) {
+            sb.append('D');
+            return;
+        }
+        if (type == Float.TYPE) {
+            sb.append('F');
+            return;
+        }
+        if (type == Byte.TYPE) {
+            sb.append('B');
+            return;
+        }
+        if (type == Boolean.TYPE) {
+            sb.append('Z');
+            return;
+        }
+        if (type == Short.TYPE) {
+            sb.append('S');
+            return;
+        }
+        if (type == Void.TYPE) {
+            sb.append('V');
+            return;
+        }
+        if (type == Character.TYPE) {
+            sb.append('C');
+            return;
+        }
+        if (type.isArray()) {
+            sb.append("_3");
+            appendType(sb, type.getComponentType());
+            return;
+        }
+        sb.append('L').append(type.getName().replace('.', '_'));
+        sb.append("_2");
+    }
 
     public static int signatureElements(String sig) {
         Enumeration<Class> en = signatureParser(sig);
@@ -148,13 +205,19 @@
                         return Character.TYPE;
                     case 'L':
                         try {
-                            int up = sig.indexOf("_2");
-                            String type = sig.substring(1, up);
+                            int up = sig.indexOf("_2", pos);
+                            String type = sig.substring(pos, up);
                             pos = up + 2;
-                            return Class.forName(type);
+                            return Class.forName(type.replace('_', '.'));
                         } catch (ClassNotFoundException ex) {
-                            // should not happen
+                            throw new IllegalStateException(ex);
                         }
+                    case '_': {
+                        char nch = sig.charAt(pos++);
+                        assert nch == '3' : "Can't find '3' at " + sig.substring(pos - 1);
+                        final Class compType = nextElement();
+                        return Array.newInstance(compType, 0).getClass();
+                    }
                 }
                 throw new UnsupportedOperationException(sig + " at " + pos);
             }