This is the mail archive of the mailing list for the glibc project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Inline function definitions for isdigit and isxdigit?

On 09/16/2016 04:58 PM, Paul Eggert wrote:
On 09/16/2016 05:06 AM, Florian Weimer wrote:
For isxdigit, C99 and C11 make a final determination that only '0' …
'9', 'a' … 'f' and 'A' … 'F' are hexadecimal digits.

In that case, POSIX cannot override this and say that there are other
hexadecimal digits. The POSIX spec for isxdigit says "Any conflict
between the requirements described here and the ISO C standard is
unintentional. This volume of POSIX.1-2008 defers to the ISO C

POSIX says this even if there are intentional differences …

I suspect it's just something you have to say. Like in the old days, when a scholar praised and affirmed the current doctrine right at the start, but then proceeded to obliterate it in his writing.

So even if another part of POSIX allows more symbolic names
in the xdigit character class and this would seem to contradict C99,
this contradiction is unintentional and the xdigit character class must
be as specified by C99.

Yes, particularly since C99 and C11 make exceptions for locales affecting other character classes. I think the intent on the C side is that isxdigit is not locale-dependent at all.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]