From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp0 ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms11 with LMTPS id CJ67OeQjoV9bMQAA0tVLHw (envelope-from ) for ; Tue, 03 Nov 2020 09:33:24 +0000 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp0 with LMTPS id eOa2NeQjoV8yIAAA1q6Kng (envelope-from ) for ; Tue, 03 Nov 2020 09:33:24 +0000 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id 4C4919403D3 for ; Tue, 3 Nov 2020 09:33:24 +0000 (UTC) Received: from localhost ([::1]:45188 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kZsgr-0007Qe-FB for larch@yhetil.org; Tue, 03 Nov 2020 04:33:21 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:34958) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kZsgZ-0007Pc-0K for bug-guix@gnu.org; Tue, 03 Nov 2020 04:33:04 -0500 Received: from debbugs.gnu.org ([209.51.188.43]:60125) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kZsgY-0007D3-4o for bug-guix@gnu.org; Tue, 03 Nov 2020 04:33:02 -0500 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1kZsgY-0000DQ-1w for bug-guix@gnu.org; Tue, 03 Nov 2020 04:33:02 -0500 X-Loop: help-debbugs@gnu.org Subject: bug#44254: Performance of package input rewriting Resent-From: Ludovic =?UTF-8?Q?Court=C3=A8s?= Original-Sender: "Debbugs-submit" Resent-CC: bug-guix@gnu.org Resent-Date: Tue, 03 Nov 2020 09:33:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 44254 X-GNU-PR-Package: guix X-GNU-PR-Keywords: To: Lars-Dominik Braun Received: via spool by 44254-submit@debbugs.gnu.org id=B44254.1604395946767 (code B ref 44254); Tue, 03 Nov 2020 09:33:02 +0000 Received: (at 44254) by debbugs.gnu.org; 3 Nov 2020 09:32:26 +0000 Received: from localhost ([127.0.0.1]:43435 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1kZsfx-0000CI-Jq for submit@debbugs.gnu.org; Tue, 03 Nov 2020 04:32:25 -0500 Received: from eggs.gnu.org ([209.51.188.92]:34664) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1kZsfv-0000Bz-TP for 44254@debbugs.gnu.org; Tue, 03 Nov 2020 04:32:24 -0500 Received: from fencepost.gnu.org ([2001:470:142:3::e]:40433) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kZsfq-0006yJ-BO; Tue, 03 Nov 2020 04:32:18 -0500 Received: from [2a01:e0a:1d:7270:af76:b9b:ca24:c465] (port=58010 helo=ribbon) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1kZsfp-0001aI-GX; Tue, 03 Nov 2020 04:32:17 -0500 From: Ludovic =?UTF-8?Q?Court=C3=A8s?= References: <20201030084245.GB3128@zpidnp36> <87tuuavgg5.fsf@gnu.org> <20201103082343.GC3127@zpidnp36> X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 13 Brumaire an 229 de la =?UTF-8?Q?R=C3=A9volution?= X-PGP-Key-ID: 0x090B11993D9AEBB5 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 3CE4 6455 8A84 FDC6 9DB4 0CFB 090B 1199 3D9A EBB5 X-OS: x86_64-pc-linux-gnu Date: Tue, 03 Nov 2020 10:32:16 +0100 In-Reply-To: <20201103082343.GC3127@zpidnp36> (Lars-Dominik Braun's message of "Tue, 3 Nov 2020 09:23:43 +0100") Message-ID: <87tuu6g50f.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Score: -2.3 (--) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-Spam-Score: -3.3 (---) X-BeenThere: bug-guix@gnu.org List-Id: Bug reports for GNU Guix List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: 44254@debbugs.gnu.org Errors-To: bug-guix-bounces+larch=yhetil.org@gnu.org Sender: "bug-Guix" X-Scanner: ns3122888.ip-94-23-21.eu Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=pass (policy=none) header.from=gnu.org; spf=pass (aspmx1.migadu.com: domain of bug-guix-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=bug-guix-bounces@gnu.org X-Spam-Score: -1.51 X-TUID: g0/JkWL1UUnG Hi, Lars-Dominik Braun skribis: >> I guess it=E2=80=99s easy to end up creating huge object graphs. Here= =E2=80=99s an >> example of an anti-pattern: >>=20 >> (define a >> ((package-input-rewriting x) ((package-input-rewriting y) p1)))=20 >>=20 >> (define b >> ((package-input-rewriting x) ((package-input-rewriting y) p2))) >>=20 >> The correct use is: >>=20 >> (define transform >> (package-input-rewriting (append x y))) >>=20 >> (define a (transform p1)) >> (define b (transform p2)) > that sounds like a section for the cookbook :) Note that there=E2=80=99s a new section in the manual on this topic: https://guix.gnu.org/manual/devel/en/html_node/Defining-Package-Variants.= html >> It seems to me that you=E2=80=99re redefining a dependency graph, node b= y node. >> Thus, you probably don=E2=80=99t need =E2=80=98package-input-rewriting= =E2=80=99 here. What you >> did in Guix-Science commit 972795a23cc9eb5a0bb1a2ffb5681d151fc4d4b0 >> looks more appropriate to me, in terms of style and semantics. > Okay, got it. My initial concern was that rewriting the graph =E2=80=9Cby= hand=E2=80=9D (i.e. > alist-delete) would be tedious and error-prone. I haven=E2=80=99t looked closely enough. If you can define a single proced= ure that rewrites the graph, that=E2=80=99s of course better than rewriting nod= es one by one. Maybe that=E2=80=99s possible, but you need to be careful about factorizing the transformation procedure as I shown above. Thanks, Ludo=E2=80=99.