[taeric]

Assuming you mean iterators in other languages, I have seen folks bit by iterators supporting the "member" functions. That said, agreed that standard use is mostly fine.

The problem with monads, in this regard, is folks try and bend everything to them. I've seen similar with "everything can be iterated" before, and it ended as poorly as you might expect.

The basic trap comes down to the fact that many of us (yes, I'm projecting), really only understand basic algebra as defined with addition and multiplication. But a basic understanding doesn't help you see how that will abstract over working with other real life things. And as soon as you have to start dealing with non-transitive and non-associative things, the basic understanding can hurt.