On Thu, Nov 11, 2010 at 6:16 PM, Dan Doel
serialize is not at all the same in this regard. There is no class of functions that is immune to its inspection powers, presumably, because that's its whole point. But that also means that there is no class of functions for which we are justified in reasoning equationally using the standard extensional equality. The only way that would be justified is saying, "serialize doesn't exist."
Admittedly, the class of reasoning I usually use in my Haskell programs, and the one that you talked about using earlier this message, is essentially "seq doesn't exist". However, I prefer to use this class of reasoning because I would prefer if seq actually didn't exist (er, I think the implication goes the other way). Not so for serialize: I would like a serialize function, but I don't want the semantic burden it brings. If only there were a way to... oh yeah. serialize :: (a -> b) -> IO String I still don't really get what we're arguing about. Luke