Add file modes for opening a file write only

sdk/lib/io/file.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;
 
 /**
  * The modes in which a File can be opened.
  */
 class FileMode {
   /// The mode for opening a file only for reading.
   static const READ = const FileMode._internal(0);
-  /// The mode for opening a file for reading and writing. The file is
+  /// Mode for opening a file for reading and writing. The file is
   /// overwritten if it already exists. The file is created if it does not
   /// already exist.
   static const WRITE = const FileMode._internal(1);
-  /// The mode for opening a file for reading and writing to the
+  /// Mode for opening a file for reading and writing to the
   /// end of it. The file is created if it does not already exist.
   static const APPEND = const FileMode._internal(2);
+  /// Mode for opening a file for writing *only*. The file is
+  /// overwritten if it already exists. The file is created if it does not
+  /// already exist.
+  static const WRITE_ONLY = const FileMode._internal(3);
+  /// Mode for opening a file for writing *only* to the
+  /// end of it. The file is created if it does not already exist.
+  static const WRITE_ONLY_APPEND = const FileMode._internal(4);
   final int _mode;
 
   const FileMode._internal(this._mode);
 }
 
 /// The mode for opening a file only for reading.
 const READ = FileMode.READ;
 /// The mode for opening a file for reading and writing. The file is
 /// overwritten if it already exists. The file is created if it does not
 /// already exist.
 const WRITE = FileMode.WRITE;
 /// The mode for opening a file for reading and writing to the
 /// end of it. The file is created if it does not already exist.
 const APPEND = FileMode.APPEND;
 
+const WRITE_ONLY = FileMode.WRITE_ONLY;

[Mads Ager (google), 2015/06/18 12:04:48]

You should duplicate the doc comments here.

+
+const WRITE_ONLY_APPEND = FileMode.WRITE_ONLY_APPEND;
+
 
 /// Type of lock when requesting a lock on a file.
 enum FileLock {
   /// Shared file lock.
   SHARED,
   /// Exclusive file lock.
   EXCLUSIVE
 }
 
 /**
@@ skipping 817 matching lines @@
       sb.write(": $osError");
       if (path != null) {
         sb.write(", path = '$path'");
       }
     } else if (path != null) {
       sb.write(": $path");
     }
     return sb.toString();
   }
 }