The Dart libraries continue to evolve, with a new round of methods turning into getters. Florian Loitsch posted this notice to the Dart mailing list : As of r14094 Map.getKeys() has been changed to Map.keys, Map.getValues() to Map.values, and Match.start()/end()/groupCount() have been made getters. Map: https://codereview.chromium.org/11267018/diff/7001/lib/core/map.dart Match: https://codereview.chromium.org/11266050/diff/5001/lib/core/regexp.dart Examples: myMap.getKeys() is now myMap.keys. myRegExp.firstMatch("foo").start() is now myRegExp.firstMatch("foo").start. As always, the Dart encourages you to join the conversation on the Dart mailing list , ask questions on Stack Overflow , and file feature requests and bugs on dartbug.com .