Re: formatting ?: operator

[Mike Miller]

On Tue, Apr 25, 2017 at 12:19:59 -0400, 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.

In my vim configuration, when I start a new line after
"some_other_longer_condition", it auto-indents 2 × shiftwidth, so twice
the indentation level normally applied to a block indent, from the start
of the previous line.

There is a vim configuration option to auto-indent to the next character
after the previous unclosed parenthesis, which I have not bothered
enabling personally, but that would handle the above style
automatically.

I have also not bothered enabling GNU indenting style in my vim
settings, so I usually end up manually fixing the indent for single-line
vs brace-enclosed blocks.

-- 
mike