unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
From: Juri Linkov <juri@linkov.net>
To: Michael Heerdegen <michael_heerdegen@web.de>
Cc: 72229@debbugs.gnu.org
Subject: bug#72229: (setq overriding-terminal-local-map nil) in isearch-done
Date: Tue, 23 Jul 2024 20:46:33 +0300	[thread overview]
Message-ID: <86jzhcyqb2.fsf@mail.linkov.net> (raw)
In-Reply-To: <87h6cg856c.fsf@web.de> (Michael Heerdegen's message of "Tue, 23 Jul 2024 18:05:31 +0200")

>> This mechanism looks like a variable watcher enabled by
>> `add-variable-watcher'.
>> So you could add a watcher that conditionally controls variable
>> modifications.
>
> I don't think variable watchers are very helpful here.  They don't solve
> the underlying problem: potentially infinite variables of the same name
> can exist, shadowing each other, with values partly sharing structures.
>
> Using variable watchers I can see whether a variable value gets shadowed
> or unassigned using a set operation - but I can't know whether the
> previous value still exists, as binding of some other variable, and if
> it will be stored back into the variable.  Nor do I have access to old
> bindings and their values until the program assigns it back to the
> variable.
>
> I saw that in Bug#70938.  Manipulations of a variable can interfere in
> annoying ways.
>
> Functions are different.  You have only one dynamic binding (unless in
> the rare case of using `cl-letf', which is extremely rare).  And you
> always have access to it to undo any prior modification.

I remember Stefan M suggested to use function variables as much as possible
such as (defvar isearch-filter-predicate #'isearch-filter-visible), then
it's easy to add more filters with add-function.

But I'm not sure is it possible to do the same with a variable
getter function?  I mean that instead of (funcall isearch-filter-predicate)
such a getter function could be called (get-value isearch-filter-predicate)
to access the variable value.





  reply	other threads:[~2024-07-23 17:46 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-07-21 14:49 bug#72229: (setq overriding-terminal-local-map nil) in isearch-done Michael Heerdegen via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-07-22 12:49 ` Michael Heerdegen via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-07-23  6:32   ` Juri Linkov
2024-07-23 11:29     ` Eli Zaretskii
2024-07-23 17:54       ` Juri Linkov
2024-07-23 16:05     ` Michael Heerdegen via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-07-23 17:46       ` Juri Linkov [this message]
2024-07-24 16:42         ` Michael Heerdegen via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-07-24 17:27           ` Drew Adams via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-07-24 20:12             ` Michael Heerdegen via Bug reports for GNU Emacs, the Swiss army knife of text editors

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/emacs/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=86jzhcyqb2.fsf@mail.linkov.net \
    --to=juri@linkov.net \
    --cc=72229@debbugs.gnu.org \
    --cc=michael_heerdegen@web.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).