Made old dart:json library use convert to parse JSON.

sdk/lib/json/json.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.
 
 /**
  * Utilities for encoding and decoding JSON (JavaScript Object Notation) data.
  */
 
 library dart.json;
 
+import "dart:convert";
+
 // JSON parsing and serialization.
 
 /**
  * Error thrown by JSON serialization if an object cannot be serialized.
  *
  * The [unsupportedObject] field holds that object that failed to be serialized.
  *
  * If an object isn't directly serializable, the serializer calls the 'toJson'
  * method on the object. If that call fails, the error will be stored in the
  * [cause] field. If the call returns an object that isn't directly
  * serializable, the [cause] will be null.
  */
 class JsonUnsupportedObjectError extends Error {

[floitsch, 2013/08/27 13:27:50]

Didn't you want to reexport these?
Otherwise a user of dart:json won't be able to catch with
JsonUnsupportedObjectError.

[Lasse Reichstein Nielsen, 2013/08/28 08:02:59]

Absolutely. Wonder where the export statement got lost.

   /** The object that could not be serialized. */
   final unsupportedObject;
   /** The exception thrown by object's [:toJson:] method, if any. */
   final cause;
 
   JsonUnsupportedObjectError(this.unsupportedObject, { this.cause });
 
   String toString() {
     if (cause != null) {
       return "Calling toJson method on object failed.";
@@ skipping 25 matching lines @@
  * JSON values.
  *
  * The optional [reviver] function, if provided, is called once for each
  * object or list property parsed. The arguments are the property name
  * ([String]) or list index ([int]), and the value is the parsed value.
  * The return value of the reviver will be used as the value of that property
  * instead the parsed value.
  *
  * Throws [FormatException] if the input is not valid JSON text.
  */
-external parse(String json, [reviver(var key, var value)]);
-
-_parse(String json, reviver(var key, var value)) {
-  BuildJsonListener listener;
-  if (reviver == null) {
-    listener = new BuildJsonListener();
-  } else {
-    listener = new ReviverJsonListener(reviver);
+parse(String json, [reviver(var key, var value)]) {
+  if (reviver != null) {
+    var original = reviver;
+    reviver = (key, value) => original(key == null ? "" : key, value);

[floitsch, 2013/08/27 13:25:40]

Again: let's make this in a separate CL.

[Lasse Reichstein Nielsen, 2013/08/28 08:02:59]

Done.

   }
-  new JsonParser(json, listener).parse();
-  return listener.result;
+  return JSON.decode(json, reviver: reviver);
 }
 
 /**
  * Serializes [object] into a JSON string.
  *
  * Directly serializable values are [num], [String], [bool], and [Null], as well
  * as some [List] and [Map] values.
  * For [List], the elements must all be serializable.
  * For [Map], the keys must be [String] and the values must be serializable.
  *
@@ skipping 731 matching lines @@
         first = false;
       });
       sink.write('}');
       seen.removeLast();
       return true;
     } else {
       return false;
     }
   }
 }