isSpace is too slow

[Neil Mitchell]

Hi,

I'm running a particular benchmark which calls isSpace a lot
(basically wc -w). There are three ways to do the underlying space
comparison - using the Haskell Data.Char.isSpace, using the C isspace,
or using the C iswspace:

isspace: 0.375
iswspace: 0.400
Char.isSpace: 0.672

Any chance someone could speed this up?  Perhaps just replacing
isSpace with a direct call to iswspace?

On the particular benchmark I'm doing, C is 4 times faster than GHC -
if isSpace was improved this would only be twice as slow.

Thanks

Neil