Make IOSink implement StringSink

sdk/lib/io/http.dart

Index: sdk/lib/io/http.dart
diff --git a/sdk/lib/io/http.dart b/sdk/lib/io/http.dart
index 2eddf7ca202419f8c5f59e15e6832a2123389257..91461e3754b6955af880a0f512dd9a93d55c73c6 100644
--- a/sdk/lib/io/http.dart
+++ b/sdk/lib/io/http.dart
@@ -522,6 +522,14 @@ abstract class ContentType implements HeaderValue {
    * Gets the character set.
    */
   String get charset;
+
+  /**
+   * Returns the encoding based on the charset parameter. If no
+   * charset parameter is specified the default charset of ISO-8859-1
+   * will be assumed. If the charset cannot be matched with a
+   * supported encoding [:null:] is returned.
+   */
+  Encoding encoding;

[nweiz, 2013/03/06 20:31:51]

This seems like it's supposed to be read-only.

It's confusing that this and charset both exist at the same time, especially
since a programmer can't rely on [encoding] being non-null. It's also weird that
currently the only way to get an encoding from its string name is to instantiate
a ContentType and read its encoding.

I'd suggest adding an Encoding.fromName constructor and removing this field.

[Søren Gjesse, 2013/03/07 16:28:47]

Good point. Added static function fromName to Encoding and removed this.

 }