Use JavaScript's Array.sort.

dart/lib/compiler/implementation/lib/js_helper.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #library('dart:_js_helper');
 
 #import('dart:coreimpl');
 
 #source('constant_map.dart');
 #source('native_helper.dart');
@@ skipping 1394 matching lines @@
     JS('void', r'#.runtimeTypeCache[#] = #', JS_CURRENT_ISOLATE(), key,
        runtimeType);
   }
   return runtimeType;
 }
 
 String getRuntimeTypeString(var object) {
   var typeInfo = JS('Object', r'#.builtin$typeInfo', object);
   return JS('String', r'#.runtimeType', typeInfo);
 }
+
+compareHelperNull(compare, a, b) {
+  if (const NullSentinel() == a) {
+    a = null;
+  }
+  if (const NullSentinel() == b) {
+    b = null;
+  }
+  compare(a, b);

[Lasse Reichstein Nielsen, 2012/10/18 11:54:50]

return result?
(I.e., is this tested? :)

+}
+
+compareHelper(compare, a, b) => compare(a, b);
+
+class NullSentinel {
+  const NullSentinel();
+}