Re: Setting up user defined texinfo headlines using outline-heading-alist

[Christopher Dimech]

> Sent: Friday, May 14, 2021 at 3:56 PM
> From: "Stefan Monnier via Users list for the GNU Emacs text editor" 
> <help-gnu-emacs@gnu.org>
> To: help-gnu-emacs@gnu.org
> Subject: Re: Setting up user defined texinfo headlines using 
> outline-heading-alist
>
> > I would be grateful for some explanation of variables "outline-regexp" and
> > "outline-heading-alist".
>
> `outline-regexp` is the most important setting for outline.el since it
> defines which lines are considered headings.
>
> `outline-heading-alist` is a relatively late addition to `outline.el`,
> very rarely used.  Basically it's just there for `outline-promote` and
> `outline-demote`.

Is it usual that we use the same heading name and level declaration
(texinfo-section-list in our case) for both "outline-regexp" and for
"outline-heading-alist"?

> > Do we really need to have both outline-heading-alist and 
> > texinfo-section-list,
>
> Of course: `texinfo-section-list` is the variable that defines for
> `texinfo.el` the sectioning commands that are in use.  It can be set by
> the user to adapt to their own Texinfo needs.
>
> `outline-heading-alist` is used as the way for `texinfo.el` to tell
> `outline.el` which heading promotes/demotes to which.

If "outline-regexp" is the most important setting, whilst 
"outline-heading-alist"
is rarely used, we can just set "texinfo-section-list" and "outline-regexp" and
introduce the "promotes/demotes" capability automatically from 
"texinfo-section-list".

Then users could simply set just "outline-regexp" only.  Then again, we could
set outline-regexp directly without using "texinfo-section-list".

The texinfo.el states that

              ;; We should merge `outline-heading-alist' and
              ;; `texinfo-section-list'.  But in the mean time, let's
              ;; just generate one from the other.

We should look at texinfo.el as it does need some cleaning up and 
simplification.

Regards
Christopher

>         Stefan
>
>
>