Just recently I became a fan of the iterable protocol. I knew about it for some time now but never actually integrated it on my own. I ended up using it to provide a nice API for one of my libraries and I thought that this approach worth sharing.

By my opinion one of the biggest problems in programming are dependencies. If you want to have a good well written application you should avoid dependencies between your modules/classes. There is a design pattern which could help and it's called Dependency Injection (DI). It allows you to inject objects into a class, instead of creating them there.