Added TODO.

lib/compiler/implementation/compiler.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.
 
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
 const bool REPORT_EXCESS_RESOLUTION = false;
@@ skipping 823 matching lines @@
     }
     if (element === null) {
       element = currentElement;
     }
     Token position = element.position();
     Uri uri = element.getCompilationUnit().script.uri;
 
     // TODO(ager,johnniwinther): The patch support should be
     // reworked to allow us to get rid of this.
     if (element.isPatched) {
-      position = element.patch.position();
-      uri = element.patch.getCompilationUnit().script.uri;
+      // TODO(johnniwinther,karlklose): create a subtype of Element for
+      // patchable elements or move the patch field to Element.
+      var patched = element;
+      position = patched.patch.position();
+      uri = patched.patch.getCompilationUnit().script.uri;
     }
 
     return (position === null)
         ? new SourceSpan(uri, 0, 0)
         : spanFromTokens(position, position, uri);
   }
 
   Script readScript(Uri uri, [ScriptTag node]) {
     unimplemented('Compiler.readScript');
   }
@@ skipping 92 matching lines @@
  * information in the generated error message.
  */
 bool invariant(Spannable spannable, var condition, {String message: null}) {
   // TODO(johnniwinther): Use [spannable] and [message] to provide better
   // information on assertion errors.
   if (condition is Function){
     condition = condition();
   }
   return spannable != null && condition;
 }