On Sat, 6 Sep 2008, Nicolas Pouillard wrote:
Excerpts from C.M.Brown's message of Fri Sep 05 22:12:05 +0200 2008:
Can you give an example? I don't see how that can be done using Control.Monad.State(.Strict).State, unless invocations of put or modify are considered side effects.
Actually, yes, sorry; I do see your point. I guess it's just IO then.
Technically, even the IO monad is pure, that's just the runtime-system that consume your 'main' function that perform effects (and unsafeP...).
But, sure the IO monad does have side-effects? I'm confused as to how it could be pure. Could you explain?
That's an important point to grasp about the way we do effects in a pure language.
Once we've understood that point one tend to be a little less precise and consider IO as effect-full.
I consider IO to be effect-full anyway - I can't see how it isn't! Thanks, Chris.