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Re: C23: asctime is obsolescent

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Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
> Richard Damon <Richard@Damon-Family.org> writes:
>> On 1/2/23 11:11 AM, Tim Rentsch wrote:
>>> Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:
>>>> In the latest C23 draft:
>>>>      https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3047.pdf
>>>> the descriptions of the __DATE__ and __TIME__ macros refer to the
>>>> asctime() function.
>>>>
>>>> That's not new.  What's new is that asctime() is deprecated.
>>>>
>>>> Referring to a deprecated function isn't really a problem, but if
>>>> asctime() is actually removed in a future standard the descriptions of
>>>> __DATE__ and __TIME__ will need to be updated.
>>>>
>>>> It would also be nice to have a new macro that expands to the current
>>>> date in the form "YYYY-MM-DD".  I do not suggest changing the behavior
>>>> of __DATE__, but perhaps something like __ISODATE__ could be added.
>>>> Question:  If this is done, should __DATE__ be deprecated?
>>>
>>> It seems pointless to add __ISODATE__ if __DATE__ is retained, and
>>> worse than pointless to add __ISODATE__ and then remove __DATE__.
>>
>> Why?  What is wrong with having macros to get a value in different
>> formats.  Different applications may well want either one.
>
> To my way of thinking, the symbol __DATE__ is defined in an ISO
> document, so it already qualifies as an ISO date.  To have
> another symbol named __ISODATE__ is redundant if it means the
> same thing as __DATE__, or confusing if it means something
> different.  If it's important to have a symbol for a different
> format defined in some other ISO standard, the symbol name should
> include some indication of where the format comes from, in a
> similar manner to __STDC_IEC_559__, for example.
>
>> Almost all my programs currently use __DATE__ (and __TIME__) to embed
>> build information into the program.  I could see applications where
>> having the ISO formatted date would be useful, as it has some very
>> useful properties (like sortability)
>
> I'm okay with having another date format.  I just don't think the
> symbol that gives it should be named __ISODATE__, because that's
> confusing.

The format is from ISO 8601, but I would oppose calling the new macro
__ISO_8601_DATE__, because longer and more difficult to remember.  My
intent is to provide an *easy* way to embed the compilation date as a
string in an executable in a reasonable format.  Inserting "_8601_" into
the name doesn't add sufficient value, and __ISODATE__ is sufficiently
clear.  And it's perfectly possible for the C standard to refer to a
YYYY-MM-DD format without mentioning the ISO 8601 standard.

The only reason to keep the current __DATE__ in the standard is backward
compatibility (and yes, that's an *extremely* compelling reason).  If I
were adding this to a new language, there would just be a __DATE__ macro
that expands to "YYYY-MM-DD"; it would never occur to me to build
something into the language that expands to "Mmm DD YYYY".  Adding "ISO"
to the new name is a concession to backward compatibility.  

Not every name has to describe its origin, and nobody seeing the name
__ISODATE__ is going to think that the ISO standard it refers to is the
ISO C standard.  I disagree with your assertion that it would be
confusing.

And if your problem with the name __ISODATE__ is the "ISO" is confusing,
you could have said that in the first place.

Do you have a suggestion for a better name?

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for XCOM Labs
void Void(void) { Void(); } /* The recursive call of the void */

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C23: asctime is obsolescent Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-11-23 18:12 -0800
  Re: C23: asctime is obsolescent Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-01-02 08:11 -0800
    Re: C23: asctime is obsolescent Richard Damon <Richard@Damon-Family.org> - 2023-01-02 12:11 -0500
      Re: C23: asctime is obsolescent Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-01-29 10:33 -0800
        Re: C23: asctime is obsolescent Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-29 16:49 -0800
          Re: C23: asctime is obsolescent Pete Forman <petef4+usenet@gmail.com> - 2023-01-30 23:23 +0000
          Re: C23: asctime is obsolescent Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-07-20 10:11 -0700
            Re: C23: asctime is obsolescent Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-07-20 15:04 -0700
              Re: C23: asctime is obsolescent Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-08-13 15:26 -0700
                Re: C23: asctime is obsolescent Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-08-13 16:47 -0700
                Re: C23: asctime is obsolescent Jakob Bohm <jb-usenet@wisemo.com.invalid> - 2023-08-17 21:18 +0200
                Re: C23: asctime is obsolescent Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-08-17 13:14 -0700
                Re: C23: asctime is obsolescent Jakob Bohm <jb-usenet@wisemo.com.invalid> - 2023-08-18 01:26 +0200
                Re: C23: asctime is obsolescent Pete Forman <petef4+usenet@gmail.com> - 2023-08-21 17:42 +0100
                Re: C23: asctime is obsolescent Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-08-29 02:37 -0700
    Re: C23: asctime is obsolescent Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-02 16:47 -0800
      Re: C23: asctime is obsolescent David Brown <david.brown@hesbynett.no> - 2023-01-03 09:40 +0100
      Re: C23: asctime is obsolescent Pete Forman <petef4+usenet@gmail.com> - 2023-01-03 15:15 +0000
        Re: C23: asctime is obsolescent Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-03 10:35 -0800
        Re: C23: asctime is obsolescent Phil Carmody <pc+usenet@asdf.org> - 2023-01-04 18:22 +0200
          Re: C23: asctime is obsolescent James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-04 15:04 -0500
      Re: C23: asctime is obsolescent Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-01-29 10:43 -0800
  Re: C23: asctime is obsolescent Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-01-02 08:20 -0800
  Re: C23: asctime is obsolescent Kaz Kylheku <864-117-4973@kylheku.com> - 2023-07-20 17:29 +0000
    Re: C23: asctime is obsolescent Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-07-20 15:20 -0700

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