Three states

[brnstnd at stealth.acf.nyu.edu]

In article <16388 at haddock.ima.isc.com> karl at haddock.ima.isc.com (Karl Heuer) writes:
> I can imagine a situation, e.g. a variant of ctype where is_lower(c) returns
> TRUE or FALSE normally, or ERROR if c is out of range.  But I would think
> that this would be rare usage, and not worthy of being part of the type.

Bad example: somehow I never find that I already know isascii(c) before
calling isdigit(c), so for ``portability'' I always have to use both.
So it wouldn't be rare usage. On the other hand, I also see absolutely
no use for a three-valued isdigit above a simple isascii && isdigit; I
suspect most other programmers agree.

---Dan