[EMAIL PROTECTED] (Marcin 'Qrczak' Kowalczyk) wrote,
> Wed, 27 Sep 2000 00:22:05 +1100, Manuel M. T. Chakravarty <[EMAIL PROTECTED]>
>pisze:
>
> > Hmm, this seems like a shortcoming in the Haskell spec. We have all
> > these isAlpha, isDigit, etc functions, but I can't get at a list of,
> > say, all characters for which isAlpha is true.
>
> You can: filter isAlpha ['\0'..'\xFFFF']
> (don't use maxBound here because it's too large and we know that
> currently there are no isAlpha characters outside this range).
>
> Working on large explicit lists is inefficient. 45443 characters
> are isAlpha. A lexer should be designed to avoid using a full list.
You are right, just having a list of the characters is to
naive an approach. But this re-enforces may point, we need
an _efficient_ way of getting at the unicode ranges for
certain character classes. H98 is seems to be lacking some
features for practical use of unicode - the header to the
standard library `Char' actually admits that
This module offers only a limited view of the full Unicode
character set; the full set of Unicode character
attributes is not accessible in this library.
Manuel
