From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Elisp manual: Note that created faces cannot be removed. Date: Mon, 22 Jul 2019 17:33:40 +0300 Message-ID: <83ef2iqgu3.fsf@gnu.org> References: <20190720183715.GC27030@ACM> <83a7d8sg7w.fsf@gnu.org> <838ssssg4v.fsf@gnu.org> <20190720202608.GD27030@ACM> <837e8crui6.fsf@gnu.org> <20190722100209.GA5933@ACM> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="266245"; mail-complaints-to="usenet@blaine.gmane.org" Cc: npostavs@gmail.com, emacs-devel@gnu.org To: Alan Mackenzie Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Jul 22 16:34:04 2019 Return-path: Envelope-to: ged-emacs-devel@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 1hpZO8-00178V-05 for ged-emacs-devel@m.gmane.org; Mon, 22 Jul 2019 16:34:04 +0200 Original-Received: from localhost ([::1]:34150 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hpZO6-0003kO-O3 for ged-emacs-devel@m.gmane.org; Mon, 22 Jul 2019 10:34:02 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:38024) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hpZNz-0003kB-TO for emacs-devel@gnu.org; Mon, 22 Jul 2019 10:34:00 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:59796) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hpZNz-0007vL-Dv; Mon, 22 Jul 2019 10:33:55 -0400 Original-Received: from [176.228.60.248] (port=1714 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1hpZNx-00034X-V8; Mon, 22 Jul 2019 10:33:55 -0400 In-reply-to: <20190722100209.GA5933@ACM> (message from Alan Mackenzie on Mon, 22 Jul 2019 10:02:09 +0000) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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:238788 Archived-At: > Date: Mon, 22 Jul 2019 10:02:09 +0000 > Cc: emacs-devel@gnu.org, Noam Postavsky > From: Alan Mackenzie > > Sorry to go on about this (trivial) point, but I'm not happy about my > proposed text any more. With the mechanism pointed out by Noam, it > clearly _is_ possible to undefine a face, but it's unsafe. > > So, using "undefine" rather than "remove" (suggested to me by private > email), and inserting the word "safely", I now propose this: > > diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi > index 276d60b21a..4ae0bba723 100644 > --- a/doc/lispref/display.texi > +++ b/doc/lispref/display.texi > @@ -2476,6 +2476,10 @@ Defining Faces > usual procedure is to define a face with @code{defface}, and then use > its name directly. > > +@cindex face (non-removability of) > +Note that once you have defined a face (usually with @code{defface}), > +you cannot later undefine this face safely, except by restarting Emacs. That's fine with me, but unlike you, I don't really see a difference: for the reader of the ELisp manual "cannot undefine safely" and "cannot remove" are identical for all practical purposes. Moreover, "undefine a face" is not really well-defined.