Am Freitag, 11. Januar 2008 11:33 schrieben Sie: > Wolfgang Jeltsch <[EMAIL PROTECTED]> writes: > > However, the fact that (0 / 0) == (0 / 0) yields False is quite shocking. > > It doesn’t adhere to any meaningful axiom set for Eq. > > Tough luck, but that's how floating point works, and what the > numericalists know, and possibly even love (although I have my > doubts). Sanitizing this behavior would make Haskell less usable for > real-world numerical problems.
The IEEE floating point equivalence test has to yield false when comparing NaN with NaN. Haskell’s (==) has to yield True or undefined when comparing a value with itself. So Haskell’s (==) just has to be different from the IEEE floating point equivalence test. What about providing a separate function for the latter? > As a compromise, what about an option to make NaN (and presumably the > infinities) cause an immediate exception? (And, cetero censeo, > exceptions for Int overflow as well.) This would be far better (and far more Haskell-like). > -k Best wishes, Wolfgang _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
