Gabi
Thank you Ertugrul,
I think I got it now. My lesson here is to avoid recursion as much possible and use foldr' instead.There are too many pitfalls.
That's not what I wanted to say. It's good to understand recursion and non-strict semantics, so that you can use them together to write great programs. =) However, as soon as you start speaking Haskell fluently, you won't write out many recursions explicitly anymore. For most things there are combinators of some type, which you can use to express what you want. Finally you will like monads, because most programming patterns can be expressed conveniently in terms of them. That includes stateful computation, aborting, resuming, undoing, nondeterminism, failability, probabilistic computation and an arbitrary mixture of them. Greets Ertugrul -- nightmare = unsafePerformIO (getWrongWife >>= sex) http://blog.ertes.de/