On Fri, 11 Jan 2008 14:21:45 +0200,
Ketil Malde:
Wolfgang Jeltsch:
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.
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.)
People, you are monsters. First, despite the *common, well known* truth that Haskell is not Mathematics, this illusion seems to be extremely persistent! Haskell is a victim - no, some users are victims of its success as a formal language, not just as a coding tool... They *want* to have Eq as they imagine the equality, including the comparison between incomparable. This is BTW a long standing philosophical problem. For centuries some speculative guys tried to analyse such "assertions" as God == God, or death==death. Or myself==myself. Of course, even if they produced some cute conclusions, they had no whatsoever sense for the others. Now we have the modern variants of it: NaN == NaN, bottom == bottom ...
Well, Haskell has this "referential transparency" thing which say that a function is a function and you will never be able to build anything else :-) ________ Information from NOD32 ________ This message was checked by NOD32 Antivirus System for Linux Mail Servers. part000.txt - is OK http://www.eset.com