Macro to exclude from filling (Re: bug#51762: 13.0.14; environment formating)

[Ikumi Keita]

[ Changing CC address to auctex-devel@gnu.org ]

>>>>> Arash Esbati <arash@gnu.org> writes:
>> According to the comment, lines ending with `\\' are excluded from
>> filling on purpose, though I'm not sure why. Perhaps for the cases
>> inside environments like tabular, array, align etc.?

> Ah, I see.  Sorry for missing that.  While we're at it, should we also
> cater for \newline and \linebreak?  Currently, they handled as normal
> macro.  It should be easy to add them to the regexp.

> WDYT?

Hmm, I'm not sure. If my guess is correct, it wouldn't appropriate to
deal \newline and \linebreak the same way as \\, since they aren't
equivalent in tabular-like environments (that is, alignments are
specified by & signs). For example,
----------------------------------------------------------------------
\documentclass{article}
\begin{document}
\begin{tabular}{ccc}
  ab & cd & ef \\
  gh & ij & kl \newline
  mn & op & qr
\end{tabular}
\end{document}
----------------------------------------------------------------------
leads to the following error:
----------------------------------------------------------------------
./xyz.tex:6: Extra alignment tab has been changed to \cr.
<recently read> \endtemplate 
                             
l.6   mn &
           op & qr
----------------------------------------------------------------------

On the other hands, it may be make sense to include lines ending with \\
in filling outside such environments.

Regards,
Ikumi Keita