[AUCTeX-devel] Re: Insertion of leading new line with C-c C-s

[Christian Schlauer]

[This is a follow-up to a thread from last december, see
<URL:http://article.gmane.org/gmane.emacs.auc-tex/5093>]

Ralf Angeli <address@hidden> writes:

> * Christian Schlauer (2004-12-02) writes:
>
>> When you press `C-c C-s' to insert a section, the first thing that
>> happens is that AUCTeX inserts a new line at point in the buffer [1].
>> I don't like it for two reasons:
>>
>> 1. I sometimes accidentally press `C-c C-s', and then `C-g' is not
>>    sufficient to abort, one also has to do `C-_'.
>
> I find this annoying as well.
>
>> 2. The new line is always inserted [1], even if there is already a
>>    blank line before point. I don't want two blank lines in front of a
>>    \section, so I always have to remove it.
> [...]
>> I would prefer to remove the two lines, but bundling the modification
>> of the buffer in `LaTeX-section-section' and thus delaying the
>> insertion of the new line would be better than the current state, too.
>> But in the second case, I would prefer a smarter mechanism that
>> doesn't add a new line if there is already a new line before point.
>
> I like this last suggestion.  One could check if the return value of
> `(save-excursion (skip-chars-backward "\n\f"))' is less than -1.  (Not
> sure if "\f" is needed, but IIRC there were problems with XEmacs if it
> wasn't included.)

Hi,

I attach a patch that does the right thing: it inserts a new line only
if the previous line is not empty or does not start with `[possible
whitespace]\begin'. The latter is to avoid things like

\begin{some-environment}

  \section{blah}

where a blank line between the beginning of the environment and the
section is not wanted.

I couldn't use `skip-chars-backward' as suggested by Ralf because that
didn't work when the section is already indented, for example when the
section is within a `multicols' environment. Try to insert sections in
the following document, and you will see that the code `does the right
thing':

\documentclass{article}
\usepackage{multicol}
\begin{document}
\section{foo 1}
\label{sec:foo-1}

\begin{multicols}{2}
  
\end{multicols}
\end{document}

(There is one case where the code does not do the right thing: when
point is placed behind \begin{some-environment}-!-. But point will
never be there when people use `C-c C-e' and `C-c C-s', so I think
this case can be ignored.)

Here is a ChangeLog entry:

--8<---------------cut here---------------start------------->8---
2005-04-03  Christian Schlauer  <address@hidden>

        * latex.el (LaTeX-section): Fix typo in doc string.  Remove code
        that almost always inserts a new line.
        (LaTeX-section-section): Fix doc string.  Add code that
        conditionally inserts a new line (which also bundles the
        modification of the buffer in this function).
        (LaTeX-section-hook): Fix typo in doc string.
--8<---------------cut here---------------end--------------->8---

A short explanation of the code/the regexp used is given in the
comment in front of it in `LaTeX-section-section'.

About the fixed typos and doc fixes: `determinate' is an adjective,
and in `LaTeX-section-section', `assumes' should be `assume' (plural),
and I took the chance and rephrased the doc string a little as well.

Regards,
-- 
Christian Schlauer