<i>Dart views types as helpful documentation and a way to help tools assist with things, period. I actually find it rather refreshing to have a language that treats types as just documentation since that is really what they are for the programmer</i><p>But, just like documentation, if it gets out of date you're really wonked.<p>I'd prefer something that is both useful as documentation <i>and</i> is used by the compiler (a la Haskell's type classes).