Documentation about Roles

Question

some time ago I found an article (Roles: Composable Units of Object Behavior) describing the pros of using Roles versus Interfaces or other ways of dealing with behavior requirements. Does any of you knows where I can find more literature about that, or knows more about Roles?

I know that that's almost a research topic, but maybe someone (maybe some Perl programmer) has tried something with it (Moose?).

Note: the reason for adding tag "perl" is that maybe Perl programmers are more likely to give an answer.

Answer 1

For Moose based examples, you should check this and that example and this specification.

ETA: For the theoretical aspects, see this page