Re: Synthetic 'unless' keyword

From	David Brown <david.brown@hesbynett.no>
Newsgroups	comp.lang.c
Subject	Re: Synthetic 'unless' keyword
Date	2016-08-04 12:21 +0200
Organization	A noiseless patient Spider
Message-ID	<nnv4ut$sh9$1@dont-email.me> (permalink)
References	<e0gh38F2552U1@mid.uni-berlin.de>

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On 04/08/16 11:44, Jens Thoms Toerring wrote:
> Hi,
> 
>   everyone uses 'if' probably hundreds of times a day.
> But in some situations I'd feel that being able to use
> 'unless' instead, as in the trivial example
> 
>   unless (argc > 1) {
>       fprintf(stderr, "Missing argument(s)\n");
>       return EXIT_FAILURE;
>   }
> 
> might contribute to the readability of the code. Now,
> 'unless' isn't a C keyword (as it is in some other
> languages, e.g. Perl) but it seems easy to use a
> define like this
> 
> #define unless(expr) if (!(expr))
> 
> What possibly could go wrong (except that 'unless' may
> be used as a variable name somewhere and that editors
> with syntax highlighting won't recognize it)? Or would
> it be to "alien" to most C programmers?
> 

A lot of people dislike the idea of "making your own language" in C, so
you can expect a fair resistance when other people are looking at your
code.  It will be hard to maintain, and hard for anyone other than you
to understand.

But some people like to use such macros in their programming.  I think
it is not worth the effort for a single case like this, but if you find
you have a range of such macros to give your programming a significantly
different flavour, then I don't think it is unreasonable - you end up
with your own language that conveniently uses a C compiler to do the
work.  Just don't expect other C programmers to like it!

But technically, I don't see any problems other than the ones you note.

Thread

Synthetic 'unless' keyword jt@toerring.de (Jens Thoms Toerring) - 2016-08-04 09:44 +0000
  Re: Synthetic 'unless' keyword David Brown <david.brown@hesbynett.no> - 2016-08-04 12:21 +0200
  Re: Synthetic 'unless' keyword Mark Storkamp <mstorkamp@yahoo.com> - 2016-08-04 07:01 -0500
    Re: Synthetic 'unless' keyword bert <bert.hutchings@btinternet.com> - 2016-08-04 05:42 -0700
    Re: Synthetic 'unless' keyword Keith Thompson <kst-u@mib.org> - 2016-08-04 08:45 -0700
      Re: Synthetic 'unless' keyword Philip Lantz <prl@canterey.us> - 2016-08-04 21:55 -0700
      Re: Synthetic 'unless' keyword BartC <bc@freeuk.com> - 2016-08-05 10:08 +0100
    Re: Synthetic 'unless' keyword Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-08-05 01:17 -0700
      Re: Synthetic 'unless' keyword BartC <bc@freeuk.com> - 2016-08-05 10:01 +0100
        Re: Synthetic 'unless' keyword Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-08-05 04:34 -0700
      Re: Synthetic 'unless' keyword Mark Storkamp <mstorkamp@yahoo.com> - 2016-08-05 09:37 -0500
        Re: Synthetic 'unless' keyword Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-08-06 02:28 -0700
  Re: Synthetic 'unless' keyword jt@toerring.de (Jens Thoms Toerring) - 2016-08-04 13:38 +0000
  Re: Synthetic 'unless' keyword BartC <bc@freeuk.com> - 2016-08-04 15:04 +0100
  Re: Synthetic 'unless' keyword mark.bluemel@gmail.com - 2016-08-04 07:06 -0700
  Re: Synthetic 'unless' keyword Keith Thompson <kst-u@mib.org> - 2016-08-04 08:52 -0700
    Re: Synthetic 'unless' keyword supercat@casperkitty.com - 2016-08-04 09:45 -0700
      Re: Synthetic 'unless' keyword Keith Thompson <kst-u@mib.org> - 2016-08-04 10:23 -0700
        Re: Synthetic 'unless' keyword Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-04 19:39 +0100
          Re: Synthetic 'unless' keyword supercat@casperkitty.com - 2016-08-04 12:02 -0700
            Re: Synthetic 'unless' keyword Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-04 20:33 +0100
            Re: Synthetic 'unless' keyword BartC <bc@freeuk.com> - 2016-08-04 20:42 +0100
              Re: Synthetic 'unless' keyword David Brown <david.brown@hesbynett.no> - 2016-08-05 13:14 +0200
                Re: Synthetic 'unless' keyword Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-05 12:41 +0100
    Re: Synthetic 'unless' keyword mark.bluemel@gmail.com - 2016-08-05 00:53 -0700
  Re: Synthetic 'unless' keyword Jerry Stuckle <jstucklex@attglobal.net> - 2016-08-04 16:43 -0400
    Re: Synthetic 'unless' keyword David Brown <david.brown@hesbynett.no> - 2016-08-05 13:16 +0200
  Re: Synthetic 'unless' keyword jt@toerring.de (Jens Thoms Toerring) - 2016-08-04 23:16 +0000
    Re: Synthetic 'unless' keyword Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-05 00:35 +0100
    Re: Synthetic 'unless' keyword Tim Rentsch <txr@alumni.caltech.edu> - 2016-08-04 20:13 -0700
    Re: Synthetic 'unless' keyword Tim Rentsch <txr@alumni.caltech.edu> - 2016-08-05 04:57 -0700
      Re: Synthetic 'unless' keyword BartC <bc@freeuk.com> - 2016-08-05 13:15 +0100
        Re: Synthetic 'unless' keyword Tim Rentsch <txr@alumni.caltech.edu> - 2016-08-18 08:11 -0700
          Re: Synthetic 'unless' keyword BartC <bc@freeuk.com> - 2016-08-18 16:36 +0100
            Re: Synthetic 'unless' keyword supercat@casperkitty.com - 2016-08-18 10:20 -0700
  Re: Synthetic 'unless' keyword Paul N <gw7rib@aol.com> - 2016-08-07 12:56 -0700

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