Re: [SUSPECTED SPAM] Re: [Emacs-diffs] scratch/widen-less a4ba846: Replace prog-widen with consolidating widen calls

[Dmitry Gutov <dgutov@yandex.ru>]

On 12/14/17 4:01 PM, Stefan Monnier wrote:

> font-lock has always widened (except when font-lock-dont-widen is set,
> which AFAICT is only the case in rmail.el), so that's probably why no
> major mode widens (CC mode probably widens during font-lock because it
> uses functions which are also used in other circumstances where they
> need to widen).
> 
> So I don't think we need to make any changes on that front.

So, nothing to add to the manual?

Code changes would only be needed in CC Mode, of course.

>> - Similar info for syntax-propertize-function, though no violators have been
>> observed so far.
> 
> Since there are no current violators, we can fix this part of the doc
> when we fix the corresponding code.

OK. The recent change in spss cache also depends on 
synax-propertize-function not calling widen, BTW.

>> What is not included, and maybe should wait until Emacs 27:
>> - Similar consolidations of 'widen' calls for add-log-current-defun,
>> eldoc-print-current-symbol-info, beginning-of-defun-function and others. And
>> accompanying documentation (again, where should it go?).
> 
> Maybe some of the doc should be in the narrowing section, where we can
> document the contexts where the narrowing is "guaranteed"
> (e.g. font-lock and indentation).

Hmm. Currently, that page doesn't exactly describe when one should call 
'widen', and when shouldn't.

Also, the piece of documentation I'm thinking about will probably need 
to reference, again, "Some major modes need to support embedded regions 
of text whose
syntax belongs to a different major mode.  Examples include “literate
programming” source files that combine documentation and snippets of
source code..."; maybe that introduction should leave the Indentation 
Controlled by Major Mode section, and get a section of its own.

So we can refer to it from several places, at least. Or maybe put all 
mixed-major-mode considerations in it together.