On Tue, 28 Aug 2001, Simon Marlow wrote: (snip)
Note that Haskell leaves the behaviour of these exceptional conditions undefined. Hugs for example will give a program error on divide by zero, and NHC has even more interesting behaviour:
Prelude> 1/0 :: Float 34.02823669209384634633746074317682114560000000
!! Damn - that's annoying. I've come to take the existence of reasonable IEEE 754 floating point support for granted - is it really generally that bad in Haskell? Are there any libraries and whatnot that will help fix this? I like at least for plus and minus infinities and NaNs to be part of things. (-: My first thought was to learn about the FFI and do actual arithmetic and the relevant reading and showing in another language that I link with, but I fear the speed penalty, and now I think about it I might be able to reasonably transparently deal with the cases I care about in pure Haskell. I also haven't yet worked out how to tell if a string is "read"able or not, yet - if (read "45")::Integer or whatever gives an error (e.g. if I'd put "af" instead of "45"), it seems to be pretty uncatchable, which is a pain. How do I tell if an instance of reading will work, or catch that it didn't? I know things must be better than this - I must be missing something? (-: Thanks. -- Mark