Re: Export of this table fails LuaLaTeX compilation

[gerard . vermeulen]

On 12.10.2022 18:21, Max Nikulin wrote:
[...]
> > > Stewart Thomas. [BUG] Tables with square brackets do not compile in
> > > PDF (latex) export. Wed, 10 Nov 2021 11:16:10 -0500.
> > > https://list.orgmode.org/CAO12V+wB18nAN0FuDPAeN94GHdt_2nbdJtc4u7n4W3HAZbaZsA@mail.gmail.com
> > >
> > > I can not figure out an easy way to separate \\ from [b] text but to
> > > prevent the problem you have discovered. I am unsure if
> > >
> > >     \\[0pt]
> > >
> > > has no negative consequences and safe enough. I expect that LaTeX
> > > sources are not easy to read when fragile sequences of tokens are
> > > involved.
> > >
> > > I just have realized that some users might take advantage of earlier
> > > behavior as a feature:
> > >
> > > - item \\
> > >   [1cm]
> > > - item
> > >
> > > I think that [1cm] should be treated as text, however I have no idea
> > > how to allow users to specify amount of vertical space and to not
> > > limit line break to LaTeX only. @@latex:\\[1cm]@@ is not suitable 
> > > when
> > > the same text should be exported to ascii, html, etc.
[...]
> Adding \relax is my fault, I did not expect that it may break \hline.
> Such behavior should be stable over decades. The question is how to
> allow users to have square brackets in the beginning of the line
> following \\ and not break some use case.
>
> > 2. On my systems ws-butler removes the trailing whitespace.
> > 3. I edited your example with nano to add the trailing space after 
> > \relax, but it still does not compile.
>
> Sorry, I did not get your point with trailing space. LaTeX ignores
> spaces after commands (e.g. "a\relax b" becomes "ab") and in the
> beginning of the line. What I am afraid of is unintentionally
> introduce white space at the beginning of the line, e.g. if
> | a |
> | b |
> |---|
> is exported as
> {} a \\
> {} b \\
> \hline
> then cell contents will be " a" and " b", not "a" and "b".
> \relax a \\
> \relax b \\
> \hline
> has no such problem.

Sorry, I have misread or misunderstood what \relax does with spaces.
Thank you for your patient explanation -- Gerard