Implement JSON serialization to stream.

lib/json/json.dart

 // Copyright (c) 2011, 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("json");
 
 // Pure Dart implementation of JSON protocol.
 
 /**
  * Utility class to parse JSON and serialize objects to JSON.
@@ skipping 14 matching lines @@
   static int length(String str) {
     return _JsonParser.objectLength(str);
   }
 
   /**
    * Serializes [:object:] into JSON string.
    */
   static String stringify(Object object) {
     return JsonStringifier.stringify(object);
   }
+
+  /**
+   * Serializes [:object:] into [:output:] stream.
+   */
+  static void dump(Object object, StringBuffer output) {

[Anton Muhin, 2012/06/21 11:02:19]

maybe make StringBuffer an optional argument of stringify.

[podivilov, 2012/06/21 11:44:17]

I think these are just different functions, no need to merge them together. And
dump(obj, sb) shouldn't return a String.

[Anton Muhin, 2012/06/21 11:50:00]

Okay, than maybe rename it to printOn---there is an idea to drop toString
altogether and use printOn w/ very similar semantics.

On 2012/06/21 11:44:17, podivilov wrote:

[podivilov, 2012/06/21 12:03:58]

Done.

+    return JsonStringifier.dump(object, output);
+  }
 }
 
 //// Implementation ///////////////////////////////////////////////////////////
 
 // TODO(ajohnsen): Introduce when we have a common exception interface for json.
 class JSONParseException {
   JSONParseException(int position, String message) :
       position = position,
       message = 'JSONParseException: $message, at offset $position';
 
@@ skipping 348 matching lines @@
   int position = 0;
   static List<int> tokens;
 }
 
 // TODO: proper base class.
 class JsonUnsupportedObjectType {
   const JsonUnsupportedObjectType();
 }
 
 class JsonStringifier {
   static String stringify(final object) {

[Anton Muhin, 2012/06/21 11:02:19]

maybe we should drop this method altogether and move this logic into
JSON.stringify?

[podivilov, 2012/06/21 11:44:17]

It might be a good idea, but I prefer to keep this change targeted.

-    JsonStringifier stringifier = new JsonStringifier._internal();
+    StringBuffer output = new StringBuffer();
+    JsonStringifier stringifier = new JsonStringifier._internal(output);
     stringifier._stringify(object);
-    return stringifier._result;
+    return output.toString();
   }
 
-  JsonStringifier._internal()
-      : _sb = new StringBuffer(), _seen = new List<Object>() {}
+  static void dump(final object, StringBuffer output) {
+    JsonStringifier stringifier = new JsonStringifier._internal(output);
+    stringifier._stringify(object);
+  }
+
+  JsonStringifier._internal(this._sb)
+      : _seen = new List<Object>() {}

[Anton Muhin, 2012/06/21 11:02:19]

nit: please, use _seen = []

[podivilov, 2012/06/21 11:44:17]

Done.

+
   StringBuffer _sb;
   List<Object> _seen;  // TODO: that should be identity set.
-  String get _result() { return _sb.toString(); }
 
   static String _numberToString(num x) {
     // TODO: need some more investigation what to do with precision
     // of double values.
     if (x is int) {
       return x.toString();
     } else if (x is double) {
       return x.toString();
     } else {
       return x.toDouble().toString();
@@ skipping 109 matching lines @@
         first = false;
       });
       _sb.add('}');
       _seen.removeLast();
       return;
     } else {
       throw const JsonUnsupportedObjectType();
     }
   }
 }