daveroundy:
> On Wed, Mar 12, 2008 at 9:27 PM, Don Stewart <[EMAIL PROTECTED]> wrote:
> > You could consider binding directly to the C functions, if needed,
> >
> > {-# OPTIONS -fffi -#include "math.h" #-}
> >
> > import Foreign.C.Types
> >
> > foreign import ccall unsafe "math.h log10"
> > c_log10 :: CDouble -> CDouble
> >
> > log10 :: Double -> Double
> > log10 x = realToFrac (c_log10 (realToFrac x))
>
> Actually, you could almost certainly just use
>
> foreign import ccall unsafe "math.h log10" log10 :: Double -> Double
>
> since in ghc CDouble and Double are identical.
>
> It's a bit sloppier, but shouldn't cause any trouble. And I've no
> idea how realToFrac is implemented, but would worry about it behaving
> oddly... for instance when given NaNs.
It's a no-op (from the core I was looking at), and then you're not worrying
about coercing newtypes.
-- Don
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