Make IOSink implement StringSink

sdk/lib/io/string_transformer.dart

 // 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.io;
 
 /**
  * String encodings.
  */
 class Encoding {
   static const Encoding UTF_8 = const Encoding._internal("utf-8");
   static const Encoding ISO_8859_1 = const Encoding._internal("iso-8859-1");
   static const Encoding ASCII = const Encoding._internal("us-ascii");
 
+  // All aliasses (in lowercase) of supported encoding from
+  // http://www.iana.org/assignments/character-sets/character-sets.xml.
+  static Map<String, Encoding> _nameToEncoding = <String, Encoding> {
+    // ISO_8859-1:1987.
+    "iso_8859-1:1987": ISO_8859_1,
+    "iso-ir-100": ISO_8859_1,
+    "iso_8859-1": ISO_8859_1,
+    "iso-8859-1": ISO_8859_1,
+    "latin1": ISO_8859_1,
+    "l1": ISO_8859_1,
+    "ibm819": ISO_8859_1,
+    "cp819": ISO_8859_1,
+    "csisolatin1": ISO_8859_1,
+
+    // US-ASCII.
+    "iso-ir-6": ASCII,
+    "ansi_x3.4-1968": ASCII,
+    "ansi_x3.4-1986": ASCII,
+    "iso_646.irv:1991": ASCII,
+    "iso646-us": ASCII,
+    "us-ascii": ASCII,
+    "us": ASCII,
+    "ibm367": ASCII,
+    "cp367": ASCII,
+    "csascii": ASCII,
+    "ascii": ASCII,  // This is not in the IANA official names.
+
+    // UTF-8.
+    "csutf8": UTF_8,
+    "utf-8": UTF_8
+  };
+
+  /**
+   * Gets an [Encoding] object from the name of the character set
+   * name. The names used are the IANA official names for the
+   * character set (see
+   * http://www.iana.org/assignments/character-sets/character-sets.xml).
+   *
+   * The [name] passed is case insensitive.
+   *
+   * If character set is not supported [:null:] is returned.
+   */
+  static Encoding fromName(String name) {
+    if (name == null) return null;
+    name = name.toLowerCase();
+    return _nameToEncoding[name];
+  }
+
   /**
    * Name of the encoding. This will be the lower-case version of one of the
    * IANA official names for the character set (see
    * http://www.iana.org/assignments/character-sets/character-sets.xml)
    */
   final String name;
 
   /**
    * SYSTEM encoding is the current code page on Windows and UTF-8 on
    * Linux and Mac.
@@ skipping 288 matching lines @@
 
 // Utility class for decoding Windows current code page data delivered
 // as a stream of bytes.
 class _WindowsCodePageDecoder extends StreamEventTransformer<List<int>, String> {
   void handleData(List<int> data, StreamSink<String> sink) {
     sink.add(_decodeBytes(data));
   }
 
   external static String _decodeBytes(List<int> bytes);
 }