> From: Stefan Guath <stefan@automata.se>
> Date: Fri, 1 Jun 2018 12:36:00 +0200
> Cc: eliz@gnu.org, 31656@debbugs.gnu.org
>
> The very idea of shadowing the global `fill-column' in the first place breaks the Principle Of Least
> Astonishment
If that is so, then we should have gobs of astonished users since 1995.
Yes, the streets are flooded with them! But Emacs users are a tough crowd that don't complain :)
> and introduces annoyance and extra work for the user when trying to understand why the
> explicit setting of `fill-column' is not respected.
Documenting the current behavior should go a long way towards helping
users understand that, right?
Sure, but I guess I don't understand exactly what that behavior is though (see below)...
> So, I guess my basic question is what value `emacs-lisp-docstring-fill-column' tries to add?
>From my POV, the answer is clear: it allows users to have different
customizable defaults for fill-column in Emacs Lisp and elsewhere.
If that was the only intention, that functionality was already present (I guess way long before 1995) by just doing:
(add-hook 'emacs-lisp-mode-hook (lambda () (setq fill-column 80))) ;fill-column is buffer-local
E.g., in text modes, it is customary to enlarge the default to 79 or
thereabouts, but in Emacs Lisp we generally say that good style is to
make lines in doc strings no wider than 60 characters (see the ELisp
manual).
Doc strings, sure. But outside doc string, as it behaves now? Nah. But even if that was the case, then just use the buffer local fill-column in a hook (as above). No need to introduce redundant mechanisms.
> To me this entire functionality should either be removed or fixed so that its behavior reflects its current docs. In
> its current state it just malformats elisp files in unexpected ways. Or am I missing something?
I'm sorry, but after so many years we had this working,
But it has never been working. If we by "working" mean "behaves as its name suggest, and as the doc describes" that is.
removing this
functionality is out of the question.
Yes, I can see that. Sorry, that was a bad suggestion from me.
I suggested to fix the docs to
match the implementation; if someone has other suggestions that don't
break existing behavior, or at least let users get back existing
behavior, please describe those suggestions.
Thanks.
Ok, I'll take a stab at the easy way out and just update the docs. When looking at the implementation in the function lisp-fill-paragraph, the outer or-clause seems to separate two cases: 1) if in a comment use fill-column, else 2) bind fill-column to emacs-lisp-docstring-fill-column and call fill-paragraph. Does that seem to be correct? In that case the current doc could be changed from "Value of `fill-column' to use when filling a docstring..." to "Value of `fill-column' to use in emacs-elisp-mode except in comments".
But I still think the original intent of emacs-lisp-docstring-fill-column (as described in its current doc) is useful, and would of course prefer if we rather could update the implementation to reflect that functionality instead. I'm just not knowledgeable enough to do a PR. Would it be difficult?
BTW, as a side note, I just wanted to add that this bug report is of course a very small detail. Also, if my language sounds a bit harsh, its just because I'm in a hurry. I'm really grateful to you and the community for putting in all the hard work so that people like me can use such a superior tool - thanks a million!