Enum on Float/Double
Hal Daume III
hdaume at ISI.EDU
Tue Oct 21 14:29:42 EDT 2003
This works great for when x/=0...is there a good (Haskell) solution for
the smallest positive float?
On Tue, 21 Oct 2003, Lennart Augustsson wrote:
> So this has been a while, but i think that decodeFloat,
> incrementing the mantissa, encodeFloat might work.
> But then again, it might not. :)
>
> -- Lennart
>
> Hal Daume III wrote:
> >>>My preference would be for succ (+-0) to return the smallest positive
> >>>real, since then you could define succ x to be the unique y with
> >>>x < y and forall z . z < y => not (x < z), where such a y exists, and
> >>>I'm not sure if the Haskell standard knows about signed zeros.
> >>
> >>Is this really useful? Why would you need this number? Peano
> >>artithmetic on reals? :-)
> >
> >
> > Is there any way to do this (yet)? I found a case where I really need:
> > f :: Float -> Float
> > where
> > f x is the least y such that x < y
> >
> > even if i have to FFI to C, I'd really like a solution.
> >
> > any help would be appreciated.
> >
> > - Hal
> >
> >
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> >
>
>
--
Hal Daume III | hdaume at isi.edu
"Arrest this man, he talks in maths." | www.isi.edu/~hdaume
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