Beginning of CSS parser using frog parsering infrastructure.

frog/source.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.
 
 // TODO(jimhug): This should be an interface to work better with tools.
 /**
  * Represents a file of source code.
  */
 class SourceFile implements Comparable {
+  // TODO(terry): This filename for in memory buffer.  May need to rework if
+  //              filename is used for more than informational.
+  static String IN_MEMORY_FILE = '<buffer>';
+
   /** The name of the file. */
   final String filename;
 
   /** The text content of the file. */
   String _text;
 
   /**
    * The order of the source file in a given library. This is used while we're
    * writing code for a library. A single source file can be used
    */
@@ skipping 125 matching lines @@
 
   /** Compares two source spans by file and position. Handles nulls. */
   int compareTo(SourceSpan other) {
     if (file == other.file) {
       int d = start - other.start;
       return d == 0 ? (end - other.end) : d;
     }
     return file.compareTo(other.file);
   }
 }