First version of Codecs and Converters.

sdk/lib/codec/json.dart

Index: sdk/lib/codec/json.dart
diff --git a/sdk/lib/codec/json.dart b/sdk/lib/codec/json.dart
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+// Copyright (c) 2013, 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.
+
+part of dart.codec;
+
+final JSON = new JsonCodec();
+
+/**
+ * A [JsonCodec] encodes Json-objects to strings and decodes strings to

[Lasse Reichstein Nielsen, 2013/07/12 11:50:47]

Json-objects -> JSON objects

[floitsch, 2013/07/12 16:09:15]

Done.

+ * Json-objects.

[Lasse Reichstein Nielsen, 2013/07/12 11:50:47]

JSON objects.

[floitsch, 2013/07/12 16:09:15]

Done.

+ */
+class JsonCodec extends Codec<Object, String> {
+  const JsonCodec();
+
+  /**
+   * Creates a JsonCodec with the given reviver.

[Lasse Reichstein Nielsen, 2013/07/12 11:50:47]

`JsonCodec`

[floitsch, 2013/07/12 16:09:15]

Done.

+   * The [reviver] function is called once for each object or list property
+   * that has been parsed.

[Lasse Reichstein Nielsen, 2013/07/12 11:50:47]

... has been parsed during decoding.
The key passed to the [reviver] function is the integer list index for a list
property, the map string for object properties, and `null` for the final result.

[floitsch, 2013/07/12 16:09:15]

Done.

+   */
+  factory JsonCodec.withReviver(reviver(var key, var value)) =

[Lasse Reichstein Nielsen, 2013/07/12 11:50:47]

The reviver is only for the decoder.
The encoder should have a 'replacer' function instead: 
  Object replacer(var key, var value) 
that provides the opposite operation. The returned object must be a List, Map or
basic type.

[floitsch, 2013/07/12 16:09:15]

Yes. But the current JSON implementation doesn't provide this (afaics).

+      _ReviverJsonCodec;
+
+  // TODO(floitsch): should we add "stringify" and "parse" for convenience as
+  // aliases for encode/decode?

[Lasse Reichstein Nielsen, 2013/07/12 11:50:47]

It would be redundant, and we would probably want to remove it in the long run,
so I think not.

[floitsch, 2013/07/12 16:09:15]

Done.

+
+  /**
+   * Parses the string and returns the resulting Json object.
+   *
+   * The optional [reviver] function, if provided, is called once for each
+   * object or list property parsed.
+   */
+  Object decode(String str, {reviver(var key, var value)}) {
+    return new JsonDecoder(reviver).convert(str);
+  }
+
+  JsonEncoder get encoder => new JsonEncoder();
+  JsonDecoder get decoder => new JsonDecoder(null);
+}
+
+class _ReviverJsonCodec extends JsonCodec {
+  final Function _reviver;
+  _ReviverJsonCodec(this._reviver);
+
+  Object decode(String str, {reviver(var key, var value)}) {
+    reviver = reviver == null ? _reviver : reviver;

[Lasse Reichstein Nielsen, 2013/07/12 11:50:47]

Parentheses around "reviver == null"

[floitsch, 2013/07/12 16:09:15]

Done.

+    return new JsonDecoder(reviver).convert(str);
+  }
+
+  JsonDecoder get decoder => new JsonDecoder(_reviver);
+}