Dear GHC Bug Hunters,
I found a bug in derived instances for Show that contain
`Float' numbers. Running
data MassPnt = MassPnt Float (Float, Float)
deriving (Show)
main = do
print 1.18088e+11
let p = MassPnt 1.18088e+11 (-0.768153, -0.742202)
print p
the first `print' is successfully executed, but the attempt
to output `1.18088e+11' below the constructor `MassPnt'
fails with
Fail: Char.intToDigit: not a digit
The program doesn't fail for all floating point numbers,
e.g., `0.0' is output without any problems. I used
ghc 2.05 on Linux 2.0.30
Actually, I am pretty sure that this is not the whole story,
because I also had problems applying `show' directly to some
floating point numbers. But, I couldn't reproduce this in a
small example yet.
Manuel
