From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Attaching context info to an error Date: Wed, 27 Dec 2023 14:08:01 -0500 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="5700"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: emacs-devel@gnu.org To: =?windows-1252?B?Sm/jbyBU4XZvcmE=?= Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Wed Dec 27 20:08:37 2023 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rIZGe-0001IS-I2 for ged-emacs-devel@m.gmane-mx.org; Wed, 27 Dec 2023 20:08:36 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rIZGM-0003oG-MV; Wed, 27 Dec 2023 14:08:18 -0500 Original-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 ) id 1rIZGL-0003o0-DW for emacs-devel@gnu.org; Wed, 27 Dec 2023 14:08:17 -0500 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rIZGJ-00068C-Mo for emacs-devel@gnu.org; Wed, 27 Dec 2023 14:08:17 -0500 Original-Received: from pmg2.iro.umontreal.ca (localhost.localdomain [127.0.0.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id 9731383062; Wed, 27 Dec 2023 14:08:13 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1703704092; bh=eD/FlcdHaYLAHIHPRqS/BdKe/Hr88kQBXF/C0Bf3/kQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=aH7v4TirOCp7cyU2H+cjAhy/OJGvS/PB7Dmg1PRjfrkd/7BjQDPhxPdMvDkTzHJuy gWI6FwRzHBbV15HDt8DsTAYcUvZzl+8hho+YvofaPgyz2SOTj7rUjvXzFQ6UigSVoe FuVqV6bGXgqvojm57U+XhmLuiTsi5dg6ih9keDD5DPpcDc6okR3ztEA2DNt/daZd4z jnTD/NP5ZaC/GA5NoHGgQ9n2cdbuuA9GtBEwzV0f/KTF6LMsa0KuGWJBWaIzd7pfZP 1dcmBzyKEWqbfPlV+9RnVktQqexH3VFaN/6yR52uuMwo5P/ZDK7SWkkP/5lJt0tcx6 S64aVgUA6dHmw== Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id 69B5F80BAF; Wed, 27 Dec 2023 14:08:12 -0500 (EST) Original-Received: from pastel (65-110-221-238.cpe.pppoe.ca [65.110.221.238]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id 4046B120FE8; Wed, 27 Dec 2023 14:08:12 -0500 (EST) In-Reply-To: (=?windows-1252?Q?=22Jo=E3o_T=E1vora=22's?= message of "Wed, 27 Dec 2023 18:08:25 +0000") Received-SPF: pass client-ip=132.204.25.50; envelope-from=monnier@iro.umontreal.ca; helo=mailscanner.iro.umontreal.ca X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:314260 Archived-At: >> > Anyway, as Gerd suggested, I would suggest at least supporting >> > EIEIO in this handler-bind. >> Could you give some concrete examples of things you'd (be able to) do >> with it? > Just look at anyCL program that uses conditions, there are > very many of them. One of them is Snooze [1] which uses them > to represent HTTP error codes. But these use error objects throughout. My question was about "at least supporting EIEIO in this handler-bind". > First, we'd have to be able to `signal` such objects. And then, > CLOS is good :-) you get access to lots of existing useful protocols. > initialize-instance, print-object, etc for free. [ Not clear what `initialize-instance` would be used for. I also don't think `print-object` would be super useful, but yes a generic function to compute the error message would be a natural use, tho currently we haven't even bothered to allow the `error-message` to be a function, so the non-object representation of errors doesn't seem to be what's holding us. ] More importantly, that doesn't tell me what new things we could do, most importantly how to attach context info :-) > From a CL perspective, and even other languages, using our > "error symbol with some 'error property" representation of > errors is almost self-evidently inferior to just making it > a first class object. You don't need to convince me of that, indeed. But that's not what we have right now, and it's not trivial to retro-fit it cleanly in the current system. Luckily, AFAICT it's orthogonal to `handler-bind`. Stefan