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Re: [RFC] Characters per line: from punch card (80) to line printer (132) (was: [Patch][OpenMP/OpenACC/Fortran] Fix mapping of optional (present|absent) arguments)
- From: Marek Polacek <polacek at redhat dot com>
- To: Jonathan Wakely <jwakely dot gcc at gmail dot com>
- Cc: Michael Matz <matz at suse dot de>, Thomas Schwinge <thomas at codesourcery dot com>, "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>, gcc-patches <gcc-patches at gcc dot gnu dot org>, "fortran at gcc dot gnu dot org List" <fortran at gcc dot gnu dot org>
- Date: Thu, 5 Dec 2019 13:07:09 -0500
- Subject: Re: [RFC] Characters per line: from punch card (80) to line printer (132) (was: [Patch][OpenMP/OpenACC/Fortran] Fix mapping of optional (present|absent) arguments)
- References: <firstname.lastname@example.org> <20191205151515.GS10088@tucnak> <email@example.com> <alpine.LSU.firstname.lastname@example.org> <CAH6eHdRxXmjv5w7QzQwwqez4f46rAL417v9tfoyyAauVBP1eFg@mail.gmail.com>
On Thu, Dec 05, 2019 at 05:03:43PM +0000, Jonathan Wakely wrote:
> On Thu, 5 Dec 2019 at 16:44, Michael Matz <email@example.com> wrote:
> > Hello,
> > (oh a flame bait :) )
> > On Thu, 5 Dec 2019, Thomas Schwinge wrote:
> > > So, I formally propose that we lift this characters per line restriction
> > > from IBM punch card (80) to mainframe line printer (132).
> > >
> > > Tasks:
> > >
> > > - Discussion.
> > I object to cluttering code in excuse for using sensible function names or
> > temporaries that otherwise can help clearing up code. Using 132-char
> > lines is cluttering code:
> > - long lines are harder to read/grasp: vertical eye movement is easier
> > than horizontal, and source code should be optimized for
> > reading, not writing
> > - long lines make it impossible to have two files next to each other at a
> > comfortable font size
> > - long lines are incompatible with existing netiquette re emails, for
> > instance
> > So, at least for me, that my terminals are 80 wide (but not x24) has
> > multiple reasons, and the _least_ of it is because that's what punch cards
> > had.
> C++17 introduces a nice feature, with rationale similar to declaring
> variables in a for-loop init-statement:
> if (auto var = foo(); bar(var))
> The variable is only in scope for the block where you need it, just
> like a for-loop.
> Unfortunately nearly every time I've tried to use this recently, I've
> found it's impossible in 80 columns, e.g. this from yesterday:
> if (auto __c = __builtin_memcmp(&*__first1, &*__first2, __len) <=>
> 0; __c != 0)
> return __c;
> When you're forced to uglify every variable with a leading __ you run
> out of characters pretty damn quickly.
> I can either not use the feature (and have the variable defined in a
> larger scope than it needs to be) or add fairly arbitrary line breaks:
> if (auto __c
> = __builtin_memcmp(&*__first1, &*__first2, __len)
> <=> 0; __c != 0)
> return __c;
> or try to give the variables shorter (and less meaningful) names.
> Adding line breaks or picking shorter names doesn't help readability.
> So I end up not using the feature.
> I'm loosely in favour of relaxing the rule for libstdc++ code. I don't
> really care what the rest of GCC looks like ;-)
Not using such a nice feature just because of formatting sounds really
shameful. Would the compromise of 100 chars make things any better here?