Re: formatting ?: operator

[Daniel J Sebald]

On 04/25/2017 11:35 AM, Rik wrote:
> On 04/25/2017 09:19 AM, John W. Eaton wrote:
> > On 04/25/2017 12:02 PM, Rik wrote:
> >
> > > I really like having the '?' and ':' line up vertically to show that there
> > > is alternative A and alternative B.
> >
> > I agree, which is why I might write
> >
> >   retval = (lower
> >             ? octave::math::gammainc (x, a)
> >             : 1.0 - octave::math::gammainc (x, a));
> >
> > even if the condition and the first expression will fit on a single line.
> >
> > > It seems verbose to wrap both the
> > > entire line and the test condition in parentheses, but I'm not strongly
> > > opposed if you want to use that convention.
> >
> > It's not necessary to wrap the condition.  My example could have been
> > written this way:
> >
> >    x = (some_long_condition || some_other_longer_condition
> >         ? some + expression - that / is * not + short
> >         : another + expression - that / is * also + not - short);
> >
> > I'm curious to know whether you have to do the alignment by hand or if
> > your editor (vim?) does it for you automatically.
>
> Alas, I just do it by hand.  I checked to see what astyle would do, but it
> just aligns the next line to the indent after the '=' sign.
>
> --Rik

I too align by hand because it is usually just a quick one or two 
tab-presses.  However, here is the alignment done by gvim without the 
use of Tab or Backspace when I turn on both "smartindent" and "cindent":

void junk(void)
{
    x = (some_long_condition || some_other_longer_condition
            ? some + expression = autoindented / per + C
            : another + expression - autoindented);

    y = some_expression_without < brackets
        ? question + mark / aligned + here
        : colon / aligned - here;
}

That is, all the lead characters are moved back and forth depending on 
context.  For example, after "void junk(void)" a CR will align the 
cursor with 4-space indent, but then a curly bracket '{' moves the 
character back 4-spaces.  Alignment doesn't see quite what I do but it 
is close.  Maybe I'll leave this active for a while and see how it works.

Dan