From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Lars Ingebrigtsen Newsgroups: gmane.emacs.bugs Subject: bug#21048: 24.4; Letrec docs Date: Wed, 09 Oct 2019 19:33:20 +0200 Message-ID: <87a7a9963j.fsf@gnus.org> References: <87zhiatvdw.fsf@gnus.org> <838sptvo0z.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="93353"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) Cc: rustompmody@gmail.com, 21048@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Wed Oct 09 21:37:33 2019 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iIHm9-000O9W-2J for geb-bug-gnu-emacs@m.gmane.org; Wed, 09 Oct 2019 21:37:33 +0200 Original-Received: from localhost ([::1]:55652 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iIHm7-0005xR-IK for geb-bug-gnu-emacs@m.gmane.org; Wed, 09 Oct 2019 15:37:31 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:35775) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iIFqf-0000mR-Lq for bug-gnu-emacs@gnu.org; Wed, 09 Oct 2019 13:34:11 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iIFqd-0001sX-Kh for bug-gnu-emacs@gnu.org; Wed, 09 Oct 2019 13:34:05 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:45201) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iIFqc-0001rq-Bg for bug-gnu-emacs@gnu.org; Wed, 09 Oct 2019 13:34:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1iIFqc-0003Ey-5R for bug-gnu-emacs@gnu.org; Wed, 09 Oct 2019 13:34:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Lars Ingebrigtsen Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 09 Oct 2019 17:34:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 21048 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: fixed Original-Received: via spool by 21048-submit@debbugs.gnu.org id=B21048.157064240712413 (code B ref 21048); Wed, 09 Oct 2019 17:34:02 +0000 Original-Received: (at 21048) by debbugs.gnu.org; 9 Oct 2019 17:33:27 +0000 Original-Received: from localhost ([127.0.0.1]:54022 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iIFq3-0003E9-Be for submit@debbugs.gnu.org; Wed, 09 Oct 2019 13:33:27 -0400 Original-Received: from quimby.gnus.org ([80.91.231.51]:39756) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iIFq0-0003Dy-RC for 21048@debbugs.gnu.org; Wed, 09 Oct 2019 13:33:25 -0400 Original-Received: from cm-84.212.202.86.getinternet.no ([84.212.202.86] helo=marnie) by quimby.gnus.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iIFpw-0002RU-Gj; Wed, 09 Oct 2019 19:33:23 +0200 In-Reply-To: <838sptvo0z.fsf@gnu.org> (Eli Zaretskii's message of "Wed, 09 Oct 2019 20:15:08 +0300") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:168752 Archived-At: Eli Zaretskii writes: > Thanks, but I have trouble understanding what the text you wrote > says. I think it needs clarifying, or maybe a descriptive enough > example. Yeah, it's pretty subtle what the difference is -- feel free to rewrite to make it clearer. I went through the tree looking for a real-life example of when this macro is useful, and the first half-dozen examples I looked at could have been written with let* instead and worked just as well, as far as I can tell. But I found one in elisp-mode.el and I adapted it slightly and added this to the manual: ---- For instance, here's a closure that removes itself from a hook after being run once: @lisp (letrec ((hookfun (lambda () (message "Run once") (remove-hook 'post-command-hook hookfun)))) (add-hook 'post-command-hook hookfun)) @end lisp -- (domestic pets only, the antidote for overdose, milk.) bloggy blog: http://lars.ingebrigtsen.no