----- Original Message -----
From: "Petr Kocmid" <pkocmid@[...].cz> 


>  > Perhaps  ~ch_p('x') and ~digit_p will both result to a chset as well.
>  > However, there's a problem. Character sets can support 8/16/32
>  > bits. While it is clear that ~ch_p('x') is chset<char> with everything
>  > on except 'x', and ~ch_p(L'x') will be chset<wchar_t>, what will be
>  > the type of ~digit_p? Shall it be hardcoded to  chset<char>?
> 
>  Perhaps using a chset seems to be a little overkill in certain cases.
> 
>  I have this idea, resulted from closer look in primitives.hpp: for all single character pa
rsers
which are using locale-style check call in their test function, the most efficient way to ma
ke a
complementar parser would be to add a completely new little parser, such as not_digit_p, hav
ing
return !impl::isdigit_ in underlying test().
> 
>  Then ~digit_p could map to not_digit_p and vice versa, making such complement operation na
turally
symmetric. And honoring locale, too. More, no need to hardcode anything to chset<char> .

Hmmm. Nice idea. I think this is practical (and fast!)
If there are no objections, I think I like this :-)

Cheers,
--Joel

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