This issue was originally filed by shtylman...@gmail.com

Looking at some of the dart filesystem apis, I see that the async methods for all of the operation do not accept a callback argument. This makes the usage of things like 'exists' much more verbose than needed because you have to set the existsHandler. IMHO it would be much easier and less error prone to accept the callback as the argument to exists:

File file = new File('text.txt');
file.exists((bool exists) { ... } );

The same could be said about many other APIs in dart. Thoughts?