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Re: Remembering C's operator precedence rules

From Joe Pfeiffer <pfeiffer@cs.nmsu.edu>
Newsgroups comp.lang.c
Subject Re: Remembering C's operator precedence rules
Date 2019-03-09 13:54 -0700
Organization A noiseless patient Spider
Message-ID <1bh8cb93bi.fsf@pfeifferfamily.net> (permalink)
References <87lg1o9efx.fsf@bsb.me.uk>

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Ben Bacarisse <ben.usenet@bsb.me.uk> writes:

> I was going to post this as a reply, but once finished I thought it
> should be a new thread.
>
> Prompted by recent posts about remembering C's 15 precedence levels for
> its 49 operators, I thought I would gather together some remarks about
> why I think you can work most of it out for yourself.  I certainly don't
> know them all, but I think of them in big blocks (unary, arithmetic,
> relational, and so on) which are easy to relate to each other, and only
> every now and then do I need to consider the structure within these
> blocks of operators.

<snip>

This isn't unexpected; they are in the order that seemed most intuitive
to K&R in 1974 or thereabouts (doing something like putting + above *
would have been downright perverse).

The thing is, what's most intuitive depends on everything from context
in the program to the current phase of the moon.  By the time you've got
15 levels for 49 operators, any sane programmer will be putting in some
extra parentheses here and there because it's faster than googling to
find out if they're necessary, and if I don't remember for sure in my
own code it probably isn't fair to expect someone coming along later
(possibly even me under a full moon) to have the same intuition.

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Thread

Remembering C's operator precedence rules Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-03-09 16:53 +0000
  Re: Remembering C's operator precedence rules Richard Damon <Richard@Damon-Family.org> - 2019-03-09 15:21 -0500
    Re: Remembering C's operator precedence rules Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-03-09 21:41 +0000
  Re: Remembering C's operator precedence rules Keith Thompson <kst-u@mib.org> - 2019-03-09 12:32 -0800
    Re: Remembering C's operator precedence rules Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-03-09 21:21 +0000
      Re: Remembering C's operator precedence rules Richard Damon <Richard@Damon-Family.org> - 2019-03-09 16:42 -0500
        Re: Remembering C's operator precedence rules "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-09 14:01 -0800
      Re: Remembering C's operator precedence rules Keith Thompson <kst-u@mib.org> - 2019-03-09 14:17 -0800
        Re: Remembering C's operator precedence rules Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-03-10 00:42 +0000
  Re: Remembering C's operator precedence rules Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2019-03-09 13:54 -0700
    Re: Remembering C's operator precedence rules Bart <bc@freeuk.com> - 2019-03-09 21:37 +0000
      Re: Remembering C's operator precedence rules Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-03-09 22:01 +0000
      Re: Remembering C's operator precedence rules Richard Damon <Richard@Damon-Family.org> - 2019-03-09 18:59 -0500
        Re: Remembering C's operator precedence rules Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-13 09:26 -0700
    Re: Remembering C's operator precedence rules Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-13 10:11 -0700
      Re: Remembering C's operator precedence rules Bart <bc@freeuk.com> - 2019-03-13 17:40 +0000
        Re: Remembering C's operator precedence rules Keith Thompson <kst-u@mib.org> - 2019-03-13 15:24 -0700
          Re: Remembering C's operator precedence rules Bart <bc@freeuk.com> - 2019-03-13 23:43 +0000
            Re: Remembering C's operator precedence rules Keith Thompson <kst-u@mib.org> - 2019-03-13 17:43 -0700
        Re: Remembering C's operator precedence rules Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-18 08:53 -0700
      Re: Remembering C's operator precedence rules Wouter Verhelst <w@uter.be> - 2019-03-13 22:24 +0200
        Re: Remembering C's operator precedence rules Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-13 14:06 -0700
        Re: Remembering C's operator precedence rules Ian Collins <ian-news@hotmail.com> - 2019-03-14 14:28 +1300
          Re: Remembering C's operator precedence rules scott@slp53.sl.home (Scott Lurndal) - 2019-03-14 13:35 +0000
            Re: Remembering C's operator precedence rules Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2019-03-14 06:55 -0700
            Re: Remembering C's operator precedence rules Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-03-14 16:39 +0000
              Re: Remembering C's operator precedence rules scott@slp53.sl.home (Scott Lurndal) - 2019-03-14 17:37 +0000
                Re: Remembering C's operator precedence rules Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-03-14 20:42 +0000
              Re: Remembering C's operator precedence rules Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2019-03-14 10:42 -0700
                Re: Remembering C's operator precedence rules Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-03-14 23:08 +0000
                Re: Remembering C's operator precedence rules Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2019-03-15 02:53 -0700
                Re: Remembering C's operator precedence rules Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2019-03-15 17:52 -0600
  Re: Remembering C's operator precedence rules Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-13 12:56 -0700
  Re: Remembering C's operator precedence rules Jens Stuckelberger <Jens_Stuckelberger@nowhere.net> - 2019-03-13 20:14 +0000
  Re: Remembering C's operator precedence rules fir <profesor.fir@gmail.com> - 2019-03-19 14:17 -0700

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