Re: Line breaks and brackets in LaTeX export (was: [bug] `org-latex-line-break-safe' breaks the export of verse blocks to LaTeX)

[Ihor Radchenko]

Juan Manuel Macías <maciaschain@posteo.net> writes:

> The solution of adding \relax or \empty is a good one. The problem is
> when it is applied massively and indiscriminately, bearing in mind that
> it is to prevent a problem that is, frankly, very rare. \empty is
> unlikely to have any side effects, but still, I don't like Org making
> these decisions for me and adding LaTeX code that I didn't ask for, in
> form or quantity. Isn't it possible to be more selective, like Pandoc
> does (I think), and add what needs to be added only when the problem is
> present? I don't know if the Pandoc thing has already been mentioned in
> past discussions, because these days I haven't been paying attention to
> the list.
>
> In any case, I would prefer: a) a selective solution; and if a) is not
> possible, at least b) a defcustom.

I tried to add the safe version of page break everywhere where there is
a risk of a page break followed by square brackets.

The key point: A valid Org file must be exported to a valid LaTeX file.

If you know a selective solution, patches are welcome. (I am also CCing
Daniel).

I see no issue with defcustom in general, but can you explain what
practical problems it is going to solve? I am not talking about
aesthetics of the exported LaTeX.

> This is an example I came up with of how it could be fixed selectively
> in LaTeX (big, big caveat: it's just a proof of concept and likely to
> produce errors in other contexts. I think if a LaTeX package to fix this
> isn't already out, it is either because the problem is very rare and the
> solution for particular cases is known, or because there are drawbacks
> inherent to LaTeX that I can't figure out right now):
>
> \makeatletter
>
> \def\my@protectlbrack{
>   \@ifnextchar{[}{\relax}{}
>   \@ifnextchar{*}{\relax}{}
> }
>
> \let\old@break\\
> \def\\{%
>   \old@break\my@protectlbrack}
>
> %% for tables
>
> \let\old@tabularcr\@tabularcr
> \def\@tabularcr{%
>   \old@tabularcr\my@protectlbrack}
>
> % for use the old commands
>
> \newcommand\oldbreak{\old@break}
> \newcommand\oldbreakt{\old@tabularcr}
>
> \makeatother
>
> \begin{document}
>
> lorem\\
> [ipsum]
>
> lorem\\
> *ipsum
>
> \begin{tabular}{cccc}
> a & a & a & a \\
> [a] & a & a & a \\
> *a & a & a & a \\
> \end{tabular}
>
>
> \end{document}

Won't it make it impossible to use
@@latex:\\@@
@@latex:[1em]@@

deliberately?

Note that we may also replace \\\empty with a single custom command. It
will look a bit cleaner. Not sure if it is any different from your
approach.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>