Add StringSink and update StringBuffer.

sdk/lib/core/string_buffer.dart

Index: sdk/lib/core/string_buffer.dart
diff --git a/sdk/lib/core/string_buffer.dart b/sdk/lib/core/string_buffer.dart
index d8b393583952238a7e66027ba20d0b45b86179e4..cbfcd6eee2959466b2931248935a9180ea5cc2d5 100644
--- a/sdk/lib/core/string_buffer.dart
+++ b/sdk/lib/core/string_buffer.dart
@@ -9,29 +9,69 @@ part of dart.core;
  * efficiently. Only on a call to [toString] are the strings
  * concatenated to a single String.
  */
-abstract class StringBuffer {
+class StringBuffer implements StringSink {
 
   /// Creates the string buffer with an initial content.
-  external factory StringBuffer([Object content = ""]);
+  external StringBuffer([Object content = ""]);
 
   /// Returns the length of the buffer.

[sra1, 2013/02/18 21:06:57]

Does it return the length of the buffer (could have additional capacity), or the
length of the string thus far accumulated?

Are you guaranteeing this is constant time? (The use in isEmpty would hint that
is so, but please state.)

[floitsch, 2013/02/19 14:21:17]

Done.

-  int get length;
+  external int get length;
 
-  // Returns whether the buffer is empty.
-  bool get isEmpty;
+  /// Returns whether the buffer is empty.
+  bool get isEmpty => length == 0;
 
-  /// Converts [obj] to a string and adds it to the buffer.
-  void add(Object obj);
+  /**
+   * Converts [obj] to a string and adds it to the buffer.
+   *
+   * *Deprecated*. Use [write] instead.
+   */
+  @deprecated
+  void add(Object obj) => write(obj);
+
+  external void write(Object obj);

[ahe, 2013/02/19 12:11:44]

You forgot to document all the new methods you added.

[floitsch, 2013/02/19 14:21:17]

Documentation for them is inherited.

+
+  void writeAll(Iterable objects) {
+    for (Object obj in objects) write(obj);
+  }
+
+  void writeln(Object obj) {
+    write(obj);
+    write("\n");
+  }
+
+  /**
+   * Adds the string representation of [charCode] to the buffer.
+   *
+   * *Deprecated* Use [writeCharCode] instead.
+   */
+  @deprecated
+  void addCharCode(int charCode) {
+    writeCharCode(charCode);
+  }
 
   /// Adds the string representation of [charCode] to the buffer.
-  void addCharCode(int charCode);
+  void writeCharCode(int charCode) {
+    write(new String.fromCharCode(charCode));
+  }
 
-  /// Adds all items in [objects] to the buffer.
-  void addAll(Iterable objects);
+  /**
+   * Adds all items in [objects] to the buffer.
+   *
+   * *Deprecated*. Use [writeAll] instead.
+   */
+  @deprecated
+  void addAll(Iterable objects) {
+    for (Object obj in objects) write(obj);
+  }
 
-  /// Clears the string buffer.
-  void clear();
+  /**
+   * Clears the string buffer.
+   *
+   * *Deprecated*.
+   */
+  @deprecated
+  external void clear();
 
   /// Returns the contents of buffer as a concatenated string.
-  String toString();
+  external String toString();
 }