Interesting Discussion

I've been talking Monads with folks on haskell-cafe as well as lazy-IO, and understanding strictness and where it sometimes needs to be sprinkled in to get the behavior desired from a lazy IO system.

This is sort of the price paid for wanting to completely separate one's pure data processing code from IO. The advantage of having this separation is of course in testing of code, in that pure code has referential transparency, meaning that you can call it any number of times you like, and as long as you provide the same X for input, you will always receive the same Y as a result.

By putting Input and Output operations into their own context of evaluation, we totally avoid certain classes of problems in software writing, so the effort seems worth it.

Needless to say it's been an interesting discussion, linked here.