From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: A programming puzzle with buffer-local hooks Date: Thu, 18 May 2017 12:51:01 -0400 Message-ID: References: <9bb8a8be-2cc6-f7cb-b164-13ffb77b8488@gmail.com> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1495126312 28169 195.159.176.226 (18 May 2017 16:51:52 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 18 May 2017 16:51:52 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.0.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu May 18 18:51:48 2017 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dBOeR-0007CN-Dw for ged-emacs-devel@m.gmane.org; Thu, 18 May 2017 18:51:47 +0200 Original-Received: from localhost ([::1]:54801 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBOeW-00019d-Kb for ged-emacs-devel@m.gmane.org; Thu, 18 May 2017 12:51:52 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:44756) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBOdx-00019U-L0 for emacs-devel@gnu.org; Thu, 18 May 2017 12:51:18 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dBOds-00020a-O4 for emacs-devel@gnu.org; Thu, 18 May 2017 12:51:17 -0400 Original-Received: from [195.159.176.226] (port=59539 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dBOds-00020K-Ff for emacs-devel@gnu.org; Thu, 18 May 2017 12:51:12 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1dBOdg-00063g-K6 for emacs-devel@gnu.org; Thu, 18 May 2017 18:51:00 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 13 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:hn/6ny/1QumnTag6zLzmEZHQjQs= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 195.159.176.226 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:214949 Archived-At: > The usual trick is to make the hook buffer local. Can't work because the focus events don't care about the current-buffer. > I can think of two other tricks: reference counting (every time the > mode is disabled, check whether it's enabled anywhere else), and never > removing the hook. Before removing the hook, check if there's still a buffer where the mode is activated. Stefan