Quoth Luke Palmer
This is not the sort of resistance I expected :-). Naturally my unrealistic argument applies to FFI as well; sin, if imported from C, would have to return in an appropriate structure. Not necessarily IO (I don't like the idea of a universal sin-bin -- I'd rather introduce a family of structures with well-defined meanings), but the same idea. Support for commutative monads (once we understand them) may relieve some of the pain of this approach.
Yes! I mean, I have no idea, but it seems like it's worth a look at anything that promises to replace some of the unsafePerformIO hacking with more functionally transparent ways to do the same thing. I love talking about the questionable purity of sin! but as it happens, since I don't do that much geometry I am without sin anyway. Donn