Subject: Re: bug#52290: 28.0.90; Undocumented generalized variables

From: Lars Ingebrigtsen <[email-masked]>
Date: Sun, 05 Dec 2021 03:52:43 +0100

Michael Heerdegen <[email-masked]> writes:

> I only wanted to note that some generalized vars might be more useful
> with `cl-letf' than with plain setf, you get some extra kinds of
> excursions gratis (sometimes doesn't work as expected though).  Example:
>
> #+begin_src emacs-lisp
> (cl-letf (((cons (point-min) (point-max))
>            (cons (line-beginning-position) (line-end-position))))
>         (recursive-edit))
> #+end_src

That's...  quote obscure.  😀

Being able to say `(decf (point))' seems kinda nice, but I think even
that is a bit on the obscure side.  I.e., all the generalised variables
that are used for side effect (as opposed to mutating an explicit
object) are liable to cause confusion.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no