On Sun, Oct 7, 2012 at 8:00 PM, Michael Orlitzky
I'm trying to use,
http://hackage.haskell.org/package/numbers-3000.0.0.0
to get better precision "for free" out of some numerical code. I ran into an issue pretty quickly, though. In Data.Number.BigFloat, we have,
data BigFloat e = BF (Fixed e) Integer deriving (Eq, Ord)
and the derived Ord is obviously incorrect:
Prelude Data.Number.BigFloat> let x = 0.1 :: BigFloat Prec50 Prelude Data.Number.BigFloat> let y = 0.02 :: BigFloat Prec50 Prelude Data.Number.BigFloat> x < y True
That's pretty strange since the derived Ord should be the same as Fixed Ord, which itself is just a newtype over Rational (and 1%10 < 2%100 == False), did you try to convert those BigFloat back to Rational to see if they're still correct ? That may be worse than a misbehaving Ord instance. -- Jedaï