For that hypothetical Venusian locale, as discussed for 1078, it would be expected to define a VDIGIT (sic) custom LC_CTYPE charclass for specifying other character names representing digits, and then using [[:digit:][:VDIGIT:]] to test for both. Code like this couldn't be considered strictly conforming, but might qualify for NLS-conforming. Also, application-specific locales can add names to a digit definition, with the same caveat, and then [:digit:] would be different from [0-9]. Similarly, VDIGIT could include [0-9] plus other names, and then code would only need to use [:VDIGIT:] to test for both.
In a message dated 5/15/2018 4:55:20 PM Eastern Standard Time, stephane.chaze...@gmail.com writes: 2018-05-15 13:38:15 -0500, Eric Blake: > On 05/15/2018 12:50 PM, Stephane Chazelas wrote: [...] > >> digit > >> Define the characters to be classified as numeric digits. > >> > >> In the POSIX locale, only: > >> > >>0 1 2 3 4 5 6 7 8 9 > > Please read http://austingroupbugs.net/view.php?id=1078 where this wording > has been tightened to cover ALL locales, not just the POSIX locale, to > better match with C requirements on isdigit(). [...] Thanks. I somehow missed that one. Does that mean that [0-9] is also guaranteed to match on 0123456789 only? And that then [[:digit:]] in regexp/fnmatch is close to useless as it's longer than [0-9] and is a bit misleading as it suggests it would be affected by localisation (like the other character classes) while it's not. -- Stephane
