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#20153: 24.4.91; destructive add-face-text-property and string deep copying Date: Wed, 09 Oct 2019 04:25:04 +0200 Message-ID: <87a7aawt8f.fsf@gnus.org> References: <87bnjnyhtb.fsf@gmail.com> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="237526"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) Cc: 20153@debbugs.gnu.org To: Oleh Krehel Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Wed Oct 09 18:04:07 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 1iIERb-000zgL-Af for geb-bug-gnu-emacs@m.gmane.org; Wed, 09 Oct 2019 18:04:07 +0200 Original-Received: from localhost ([::1]:51902 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iIERZ-0003hS-FB for geb-bug-gnu-emacs@m.gmane.org; Wed, 09 Oct 2019 12:04:05 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:45754) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iI1sz-0001lf-JB for bug-gnu-emacs@gnu.org; Tue, 08 Oct 2019 22:39:34 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iI1fu-0000cZ-DQ for bug-gnu-emacs@gnu.org; Tue, 08 Oct 2019 22:26:03 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:42928) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iI1fu-0000cK-A8 for bug-gnu-emacs@gnu.org; Tue, 08 Oct 2019 22:26:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1iI1fu-0000Ok-3o for bug-gnu-emacs@gnu.org; Tue, 08 Oct 2019 22:26:02 -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 02:26:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 20153 X-GNU-PR-Package: emacs Original-Received: via spool by 20153-submit@debbugs.gnu.org id=B20153.15705879091465 (code B ref 20153); Wed, 09 Oct 2019 02:26:02 +0000 Original-Received: (at 20153) by debbugs.gnu.org; 9 Oct 2019 02:25:09 +0000 Original-Received: from localhost ([127.0.0.1]:51749 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iI1f3-0000NZ-9M for submit@debbugs.gnu.org; Tue, 08 Oct 2019 22:25:09 -0400 Original-Received: from quimby.gnus.org ([80.91.231.51]:50858) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iI1f2-0000NS-2d for 20153@debbugs.gnu.org; Tue, 08 Oct 2019 22:25:08 -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 1iI1ey-0001QF-NU; Wed, 09 Oct 2019 04:25:07 +0200 In-Reply-To: <87bnjnyhtb.fsf@gmail.com> (Oleh Krehel's message of "Fri, 20 Mar 2015 13:28:00 +0100") 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:168691 Archived-At: Oleh Krehel writes: > Here's an example of what I'm trying to do: > > (setq test-str-1 > #(";; This `is' a test" > 0 3 (fontified nil face font-lock-comment-delimiter-face) > 3 9 (fontified nil face font-lock-comment-face) > 9 11 (fontified nil face (font-lock-constant-face font-lock-comment-face)) > 11 19 (fontified nil face font-lock-comment-face))) > (setq test-str-2 (concat test-str-1)) > (add-face-text-property 0 (length test-str-2) 'foobar t test-str-2) > > I would like to modify `test-str-2' without touching `test-str-1'. > For that, I either need `add-face-text-property' to be non-destructive, > either w.r.t. the string or at least w.r.t. the properties of the > string, or a way to deep-copy a string. It's this code (in add_properties): /* The previous value is a list, so prepend (or append) the new value to this list. */ if (set_type == TEXT_PROPERTY_PREPEND) Fsetcar (this_cdr, Fcons (val1, Fcar (this_cdr))); else nconc2 (Fcar (this_cdr), list1 (val1)); But changing that would have pretty far-reaching consequences. I wonder whether instead Fadd_face_text_property should just (when called with a string parameter) just copy the `face' property list first? That should avoid the problem and not lead to any general slowdown. -- (domestic pets only, the antidote for overdose, milk.) bloggy blog: http://lars.ingebrigtsen.no