Now for your question, I was so inspired by it that I’m going to answer this in a whole post of itself. Thanks for commenting on this! Coincidently, I was just wondering how to people involved in the the discussion and here we are! The post should be up in a few hours and again, thanks!

Been a while – you doing well?

Now to get on-topic: you say OOP is about hiding mutable state. Isn’t it about _encapsulating_ mutable state?
Maybe it’s just a matter of wording – but ‘hidden’, in my dictionary, means that it’s totally out of reach. Encapsulated state (again, in my dictionary) can be modified, but only through controlled operations.

Regards!

The one below has class="brush:csharp" and although it is not as fancy as I hoped it would be it seems reasonably functional:

public interface IFoo
{
    public IEnumerable<Bar> Bars
    {
         get;
         set;
    }

    public abstract Bar ExecuteOnce(string message);

    public IEnumerable<Bar> ExecuteManyManyManyTimes(int times, string message) {
         var theBar = new Bar();
         for(var i = 0; i < times; i++) {
              var theBars = Bars.Where(bar => bar != theBar).Select(bar => bar.Fubar());
              foreach(var bar in theBars)
              {
                   yield return bar;
              }
         }
    }
}

Just keep in mind to replace those < and >’s with < and > respectively otherwise your comment still won’t look right.

Basic markup is apparently also allowed (quite a lot of tags actually) but please be gentle.