Beginning of CSS parser using frog parsering infrastructure.

utils/css/cssselectorexception.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.
+
+
+/** Can be thrown on any Css runtime problem includes source location. */
+class CssSelectorException implements Exception {

[jimhug, 2011/11/10 17:58:56]

Hmm...  I think that we should rename compiler exception to SourceException (or
something similar that is less awkward).  The main point of that exception type
to to contain both a message and a location both for printing nicely and uniform
tool support.  I'd add a TODO: Consider renaming CompilerException such that
this would be an appropriate subclass.  I'd also definitely not make this change
itself in this CL to minimize potential conflicts.

[terry, 2011/11/16 14:00:22]

Done.

+  final String _message;
+  final lang.SourceSpan _location;
+
+  CssSelectorException(this._message, [this._location = null]);
+
+  String toString() {
+    if (_location != null) {
+      return 'CssSelectorException: ${_location.toMessageString(_message)}';
+    } else {
+      return 'CssSelectorException: $_message';
+    }
+  }
+
+}