Received: (at submit) by debbugs.gnu.org; 2 Feb 2025 17:49:01 +0000 From debbugs-submit-bounces <at> debbugs.gnu.org Sun Feb 02 12:49:01 2025 Received: from localhost ([127.0.0.1]:36171 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>) id 1tee5d-0002X7-6X for submit <at> debbugs.gnu.org; Sun, 02 Feb 2025 12:49:01 -0500 Received: from lists.gnu.org ([2001:470:142::17]:37302) by debbugs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from <basil@HIDDEN>) id 1tee5Z-0002Wk-Tx for submit <at> debbugs.gnu.org; Sun, 02 Feb 2025 12:48:58 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <basil@HIDDEN>) id 1tee5T-00056g-AT for bug-gnu-emacs@HIDDEN; Sun, 02 Feb 2025 12:48:51 -0500 Received: from mta-10-4.privateemail.com ([198.54.122.149]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <basil@HIDDEN>) id 1tee5R-0005I5-AS for bug-gnu-emacs@HIDDEN; Sun, 02 Feb 2025 12:48:51 -0500 Received: from mta-10.privateemail.com (localhost [127.0.0.1]) by mta-10.privateemail.com (Postfix) with ESMTP id 4YmHDZ3jbhz3hhTs for <bug-gnu-emacs@HIDDEN>; Sun, 2 Feb 2025 12:48:46 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=contovou.net; s=default; t=1738518526; bh=2IWkm+rwXWluDXemSbzrYsFcENUIuCX9ukfJoVZQrzw=; h=From:To:Subject:Date:From; b=sY1rgEbHzEinR47zMa1PvstENk1+tLJJA+2LeWuFe8EL3FV7rcMPrrFWt8Ik57wSE SQZ9m2j/a5SVE2wwKt3tFS6Sy5kM8tXdKr6tuuICHvN0eZLgsfyR2Smfy5ncUcfJuX NI+/9GxTZqGcXIADkHInOXI9OAYtf9/SOsnlfwyxhBZ+ttej7iKkz/nL4tsKThTN/i wlmMlRh+MDSIy1I8jBUJzGC8PE3xqlcYxL6/oCA7obvc2YKTwAJ/iUHx+Mhv0KBcyl Y75DeMdIxWg2q1FTL2Nbb26vktbOGNjAHOisuaJ+Vqgc5ldSj2AX0wdqYpuBauNWJj ubK34k7azH4YQ== Received: from localhost (unknown [31.46.243.74]) by mta-10.privateemail.com (Postfix) with ESMTPA for <bug-gnu-emacs@HIDDEN>; Sun, 2 Feb 2025 12:48:45 -0500 (EST) From: "Basil L. Contovounesios" <basil@HIDDEN> To: bug-gnu-emacs@HIDDEN Subject: 31.0.50; Which args can cl-nintersection and cl-nset-difference mutate? X-Debbugs-Cc: Mattias =?utf-8?Q?Engdeg=C3=A5rd?= <mattias.engdegard@HIDDEN>, Stefan Monnier <monnier@HIDDEN> Date: Sun, 02 Feb 2025 18:48:40 +0100 Message-ID: <87h65cgruv.fsf@HIDDEN> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Virus-Scanned: ClamAV using ClamSMTP Received-SPF: pass client-ip=198.54.122.149; envelope-from=basil@HIDDEN; helo=MTA-10-4.privateemail.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-Spam-Score: 1.0 (+) X-Debbugs-Envelope-To: submit X-BeenThere: debbugs-submit <at> debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: <debbugs-submit.debbugs.gnu.org> List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe> List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/> List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org> List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help> List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe> Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org> X-Spam-Score: -0.0 (/) Since as far back as I can go in emacs.git history, the manual says: -- Function: cl-nintersection list1 list2 &key :test :test-not :key This is a destructive version of =E2=80=98cl-intersection=E2=80=99. I= t tries to reuse storage of LIST1 rather than copying. It does _not_ reuse the storage of LIST2. -- Function: cl-nset-difference list1 list2 &key :test :test-not :key This is a destructive =E2=80=98cl-set-difference=E2=80=99, which will = try to reuse LIST1 if possible. whereas their docstrings say: (cl-nintersection LIST1 LIST2 [KEYWORD VALUE]...) Combine LIST1 and LIST2 using a set-intersection operation. The resulting list contains all items that appear in both LIST1 and LIST2. This is a destructive function; it reuses the storage of LIST1 and LIST2 whenever possible. (cl-nset-difference LIST1 LIST2 [KEYWORD VALUE]...) Combine LIST1 and LIST2 using a set-difference operation. The resulting list contains all items that appear in LIST1 but not LIST2. This is a destructive function; it reuses the storage of LIST1 and LIST2 whenever possible. The mutates-arguments property added in Byte-compiler warning about mutation of constant values bfc07100d28 2023-05-13 11:53:25 +0200 https://git.sv.gnu.org/cgit/emacs.git/commit/?id=3Dbfc07100d28 agrees with the docstrings, but CL docs I found online, and Jo=C3=A3o's pat= ch in https://lists.gnu.org/r/emacs-devel/2023-11/msg00595.html agree with the manual. My arguments in favour of the manual: - Documented for decades in both Emacs and CL docs. - It is the weaker of the two requirements, thus backward-compatible. - Set difference implementations do not naturally benefit from modifying the second set (though I would love to see a counterexample). - Callers of cl-nintersection having to ensure both arguments are safe to mutate (e.g. through excessive copying) could diminish any performance benefit it has over cl-intersection. If there is agreement, I can follow up with a patch for our docs and tests. Thanks, --=20 Basil In GNU Emacs 31.0.50 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo version 1.18.2, Xaw3d scroll bars) of 2025-02-02 built on tais Repository revision: c91c591f0f0cc774647c32bdcf05bb3a9551e340 Repository branch: master Windowing system distributor 'The X.Org Foundation', version 11.0.12101015 System Description: Debian GNU/Linux trixie/sid
"Basil L. Contovounesios" <basil@HIDDEN>
:mattias.engdegard@HIDDEN, monnier@HIDDEN, bug-gnu-emacs@HIDDEN
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Full text available.mattias.engdegard@HIDDEN, monnier@HIDDEN, bug-gnu-emacs@HIDDEN
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