In article <ifado.list.haskell/[EMAIL PROTECTED]>,
George Russell <[EMAIL PROTECTED]> wrote:
>No, but they ARE, assuming IEEE arithmetic, discrete mathematical
>objects with an arithmetic as well defined as that on the integers.
>To do constant folding according to different rules is, IMHO,
>outrageous. One should not have to add --strict-fp for purity
>of addition to be guaranteed, instead purity should be the default,
>with perhaps a --fast-math option for people who know what they're
>doing or don't mind living dangerously. Surely this is obvious to
>Haskell programmers?
IMHO you are not right in this. See W. Kahan on the ridiculous Java
restriction in FP reproducibility. The sum of the 3 numbers is an
integer number, despite any loss of precision in intermediate results.
If you mind that this could be exploited to create side-effects, you
have to wrap FP into a monad.
--
Dipl.-Math. Wilhelm Bernhard Kloke
Institut fuer Arbeitsphysiologie an der Universitaet Dortmund
Ardeystrasse 67, D-44139 Dortmund, Tel. 0231-1084-257
