[AUCTeX] LaTeX-fill-break-at-separators (11.88.9)

[jfbu]

Hi,

I know this has been discussed prior to 11.88.9 release, but I have
a confusing problem when the same source behaves differently in two
files under the same docTeX mode

----
\documentclass{article}% same with scrdoc

\begin{document}

% Test $char37 $space added note on the implementation:
% we can roughly estimate for big

\end{document}
----

For the above foo.dtx test file, if I turn on docTeX mode and do
M-q on the paragraph, it is transformed into the expected

% Test $char37 $space added note on the implementation: we can roughly
% estimate for big

fill-column is set to 78

and

M-q (translated from <escape> q) runs the command fill-paragraph, which is an
interactive compiled Lisp function in `fill.el'.

However the very same paragraph in my big dtx file behaves differently,
it becomes under M-q

% Test $char37
% $space added note on the implementation: we can roughly estimate for big

In both, I can check that M-q is bound to same function and that

----
LaTeX-fill-break-at-separators is a variable defined in `latex.el'.
Its value is (\\\( \\\[)

Documentation:
List of separators before or after which respectively a line
break will be inserted if they do not fit into one line.

You can customize this variable.
----

Indeed if I customize the variable to uncheck all items, the problem
disappears. But why was it present to start with ?

Do you have any clue on how to debug this ? In the big bar.dtx I have
the paragraph preceded and followed by other commented paragraphs.

I have transferred about 100 lines with 50 lines before and 50 lines
after from bar.dtx into foo.dtx, Still M-q behaves correctly in foo.dtx
but in bar.dtx I have systematically the bad break

(I tried varying fill-column, does not change anything, except if big
enough for the whole paragraph to be on one single line)

The dtx is very big and trying to cut down to a mwe will be time costly

Any clue on how to debug this ?

Also I am confused by the customize buffer for
LaTeX-fill-break-at-separators

 Opening Inline Math Switches

This seems to indicate $ and \( are treated the same ?
I thought they were not from previous thread, but I misunderstood probably

I can reproduce the problem in foo.dtx if I check the

 Closing Inline Math Switches

My problem is: why do I see the bad break in bar.dtx although
Closing Inline Math Switches is not checked in the customize buffer ?


Hide Latex Fill Break At Separators:
[ ] Opening Brace
[ ] Closing Brace
[ ] Opening Bracket
[X] Opening Inline Math Switches
[ ] Closing Inline Math Switches
[X] Opening Display Math Switch
[ ] Closing Display Math Switch

Is it possible some other hook has changed something which does
not show up in the customize buffer ?

...ah ... I am starting to understand: the second $ is
interpreted here as an Opening, not Closing, math switch. The prior
50 lines were not enough to reproduce the problem.

Well, posting anyhow.

It is not coherently possible to know if $ is opening or closing,
because $ can be used for other things

for example in this buffer  the $ at this location
is not at all a math shift character but a catcode 0 escape,
could it be envisioned not to apply to $ what is thought out for \( .. \) ?

that would give an argument to people advocating \( : use it to
benefit from AUCTeX parsing.


how local is the check for $ opening or closing ?


Jean-François