Clean and create output directory when generating docs.

frog/file_system_dom.dart

 // Copyright (c) 2011, 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.
 
 #library('file_system_dom');
 
 #import('dart:dom');
 #import('file_system.dart');
 
 /**
@@ skipping 50 matching lines @@
     return result;
   }
 
   void writeString(String outfile, String text) {
     outfile = absPath(outfile);
     _fileCache[outfile] = text;
   }
 
   // Note: this is not a perf nightmare only because of caching.
   bool fileExists(String filename) => readAll(filename) != null;
+
+  void createDirectory(String path, [bool recursive = false]) {
+    throw 'createDirectory() is not implemented by DomFileSystem yet.';

[Jacob, 2011/11/16 19:59:30]

perhaps add a TODO for each of these methods?
Also, no need to include DomFileSystem in the error as that's obvious for the
callstack if someone cares.  Same for the method name itself.

[Bob Nystrom, 2011/11/17 20:44:21]

Done.

+  }
+
+  void removeDirectory(String path, [bool recursive = false]) {
+    throw 'removeDirectory() is not implemented by DomFileSystem yet.';
+  }
 }