Use browsers JSON.parse for parsing JSON.

sdk/lib/json/json.dart

Index: sdk/lib/json/json.dart
diff --git a/sdk/lib/json/json.dart b/sdk/lib/json/json.dart
index 4348767eea666865b422cd6e22b80c4042b1f1bc..3d2d615b5265fa9ea2ea3f505e2bcc8748687de7 100644
--- a/sdk/lib/json/json.dart
+++ b/sdk/lib/json/json.dart
@@ -35,21 +35,24 @@ class JsonUnsupportedObjectError implements Error {
 
 
 /**
- * Parses [json] and build the corresponding parsed JSON value.
+ * Parses [json] and builds the corresponding parsed JSON value.
  *
  * Parsed JSON values are of the types [num], [String], [bool], [Null],
  * [List]s of parsed JSON values or [Map]s from [String] to parsed
  * JSON values.
  *
- * The optional [revivier] 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 revivier will be used as the value of that property
- * instead the parsed value.
+ * 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 of the parsed
+ * value.  The top level value is passed to the reviver with the empty string as
+ * a key.
  *
  * Throws [FormatException] if the input is not valid JSON text.
  */
-parse(String json, [reviver(var key, var value)]) {
+external parse(String json, [reviver(var key, var value)]);
+
+_parse(String json, [reviver(var key, var value)]) {

[kasperl, 2013/02/06 07:07:11]

If this code is only used by the VM, it shouldn't live in the
platform-independent part of the library. That also goes for all the
implementation code below I guess.

[sra1, 2013/02/06 17:22:39]

The code can still be used by someone who needs their own custom JsonListener.
dart2js is smart enough to leave it out for 'normal' usage.

I intend to write a benchmark that uses JsonParser and the provided JsonListener
implementations to track dart2js compiled code performance which is currently
similar to VM performance.  Both are currently slower than the browser native
parser.

   BuildJsonListener listener;
   if (reviver == null) {
     listener = new BuildJsonListener();