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Groups > comp.std.c > #6192

Re: Add @ to basic character set?

From Thomas David Rivers <rivers@dignus.com>
Newsgroups comp.std.c
Subject Re: Add @ to basic character set?
Date 2020-12-07 17:02 -0500
Organization Aioe.org NNTP Server
Message-ID <5FCEA667.2000108@dignus.com> (permalink)
References <rqfeip$lrr$1@solani.org> <rqlaj0$1s77$1@gioia.aioe.org> <87zh2pe5cr.fsf@nosuchdomain.example.com>

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Keith Thompson wrote:

>Thomas David Rivers <rivers@dignus.com> writes:
>  
>
>>Philipp Klaus Krause wrote:
>>
>>    
>>
>>>I wonder if it would make sense to add @ to the basic character set.
>>>Virtually everyone is using it in comments and strings already anyway
>>>(for email addresses), and I don't see anything preventing
>>>implementations from supporting it, as it is available in both ASCII and
>>>common EBCDIC code pages:
>>>
>>>http://www.colecovision.eu/stuff/proposal-basic-@.html
>>> 
>>>      
>>>
>>Just to add to the "used as an extension" list of compilers; the Dignus
>>compilers (and the SAS/C compilers) for the mainframe use @ to be similar
>>to &, except that it can accept an rvalue.   If an rvalue is present
>>after a @, then the address of a copy is generated.  The copy is
>>declared within
>>the inner-most scope.
>>
>>This is helpful in some situations on the mainframe where pass-by-reference
>>is the norm, as in:
>>
>>  FOO(@1, @2);
>>
>>(where FOO is defined in some other language, e.g. PL/I, where the
>>parameters
>>are pass-by-reference.)
>>    
>>
>
>You can do the same thing with a compound literal starting in C99:
>
>#include <stdio.h>
>
>void FOO(int *a, int *b) {
>    printf("%d %d\n", *a, *b);
>}
>
>int main(void) {
>    FOO(&(int){1}, &(int){2});
>}
>
>I suspect the extension predates compound literals.
>
>  
>
Yep - this extension predates those.

And - very clever use of them!  It certainly does what someone would need
in this situation.

    - Dave R. -



-- 
rivers@dignus.com                        Work: (919) 676-0847
Get your mainframe programming tools at http://www.dignus.com

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Thread

Add @ to basic character set? Philipp Klaus Krause <pkk@spth.de> - 2020-12-05 08:58 +0100
  Re: Add @ to basic character set? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-12-05 10:53 -0500
    Re: Add @ to basic character set? David Brown <david.brown@hesbynett.no> - 2020-12-05 17:15 +0100
      Re: Add @ to basic character set? Philipp Klaus Krause <pkk@spth.de> - 2020-12-05 20:55 +0100
    Re: Add @ to basic character set? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-12-05 14:17 -0800
      Re: Add @ to basic character set? Francis Glassborow <francis.glassborow@btinternet.com> - 2020-12-06 12:25 +0000
        Re: Add @ to basic character set? David Brown <david.brown@hesbynett.no> - 2020-12-06 13:47 +0100
          Re: Add @ to basic character set? Richard Damon <Richard@Damon-Family.org> - 2020-12-06 08:42 -0500
            Re: Add @ to basic character set? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-12-06 14:07 -0800
              Re: Add @ to basic character set? Richard Damon <Richard@Damon-Family.org> - 2020-12-06 17:44 -0500
                Re: Add @ to basic character set? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-12-06 15:49 -0800
                Re: Add @ to basic character set? Philipp Klaus Krause <pkk@spth.de> - 2020-12-07 09:31 +0100
                Re: Add @ to basic character set? Richard Damon <Richard@Damon-Family.org> - 2020-12-07 07:24 -0500
                Re: Add @ to basic character set? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-12-07 12:16 -0800
                Re: Add @ to basic character set? Richard Damon <Richard@Damon-Family.org> - 2020-12-07 15:51 -0500
                Re: Add @ to basic character set? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-12-07 13:10 -0800
                Re: Add @ to basic character set? Andreas Schwab <schwab@linux-m68k.org> - 2020-12-07 23:52 +0100
                Re: Add @ to basic character set? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-12-07 15:27 -0800
                Re: Add @ to basic character set? Richard Damon <Richard@Damon-Family.org> - 2020-12-07 18:54 -0500
                Re: Add @ to basic character set? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-12-07 16:10 -0800
                Re: Add @ to basic character set? Richard Damon <Richard@Damon-Family.org> - 2020-12-07 18:31 -0500
                Re: Add @ to basic character set? Andreas Schwab <schwab@linux-m68k.org> - 2020-12-07 23:08 +0100
              Re: Add @ to basic character set? Philipp Klaus Krause <pkk@spth.de> - 2020-12-07 09:30 +0100
      Re: Add @ to basic character set? Philipp Klaus Krause <pkk@spth.de> - 2020-12-07 09:17 +0100
  Re: Add @ to basic character set? Thomas David Rivers <rivers@dignus.com> - 2020-12-06 16:11 -0500
    Re: Add @ to basic character set? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-12-07 12:19 -0800
      Re: Add @ to basic character set? Thomas David Rivers <rivers@dignus.com> - 2020-12-07 17:02 -0500
  Re: Add @ to basic character set? Philipp Klaus Krause <pkk@spth.de> - 2021-03-11 22:50 +0100
    Re: Add @ to basic character set? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-03-11 15:40 -0800
      Re: Add @ to basic character set? Philipp Klaus Krause <pkk@spth.de> - 2021-03-12 15:25 +0100
    Re: Add @ to basic character set? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-10 08:46 -0700

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