Add StringSink and update StringBuffer.

sdk/lib/core/string_sink.dart

Index: sdk/lib/core/string_sink.dart
diff --git a/sdk/lib/core/string_sink.dart b/sdk/lib/core/string_sink.dart
new file mode 100644
index 0000000000000000000000000000000000000000..4ba08dac818ff65103710d874c86cda2eac76c02
--- /dev/null
+++ b/sdk/lib/core/string_sink.dart
@@ -0,0 +1,27 @@
+// 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.core;
+
+abstract class StringSink {
+
+  /**
+   * Converts [obj] to a String by invoking `toString` and adds the result to
+   * this [StringSink].
+   */
+  void write(Object obj);
+
+  /**
+   * Converts [obj] to a String by invoking `toString` and adds the result to
+   * this [StringSink]. Then adds a new line.
+   */
+  void print(Object obj);
+
+  /**
+   * Adds the [charCode] to this [StringSink].
+   *
+   * This method is equivalent to `write(new String.fromCharCode(charCode))`.
+   */
+  void addCharCode(int charCode);

[kasperl, 2013/02/11 07:51:53]

Wouldn't writeCharCode be more consistent?

[Lasse Reichstein Nielsen, 2013/02/11 12:30:11]

Agree.

[floitsch, 2013/02/11 17:10:49]

Done.

[floitsch, 2013/02/11 17:10:49]

Done.

+}