From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: ludo@gnu.org (Ludovic =?iso-8859-1?Q?Court=E8s?=) Newsgroups: gmane.lisp.guile.devel Subject: Re: R6RS exception printing at the REPL Date: Thu, 02 Dec 2010 00:13:10 +0100 Message-ID: <87zkspulx5.fsf@gnu.org> References: <87sjzvnu1i.fsf@delenn.lan> <87tyjbkger.fsf@delenn.lan> <87ipzj631y.fsf@delenn.lan> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: dough.gmane.org 1291245217 27767 80.91.229.12 (1 Dec 2010 23:13:37 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 1 Dec 2010 23:13:37 +0000 (UTC) To: guile-devel@gnu.org Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Thu Dec 02 00:13:32 2010 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1PNvrg-0002n2-Ay for guile-devel@m.gmane.org; Thu, 02 Dec 2010 00:13:32 +0100 Original-Received: from localhost ([127.0.0.1]:42038 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PNvrf-0002yz-JF for guile-devel@m.gmane.org; Wed, 01 Dec 2010 18:13:31 -0500 Original-Received: from [140.186.70.92] (port=41267 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PNvra-0002vk-Tv for guile-devel@gnu.org; Wed, 01 Dec 2010 18:13:27 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PNvrZ-0002tu-LY for guile-devel@gnu.org; Wed, 01 Dec 2010 18:13:26 -0500 Original-Received: from lo.gmane.org ([80.91.229.12]:39746) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PNvrZ-0002tq-DO for guile-devel@gnu.org; Wed, 01 Dec 2010 18:13:25 -0500 Original-Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1PNvrV-0002iq-4F for guile-devel@gnu.org; Thu, 02 Dec 2010 00:13:21 +0100 Original-Received: from yoda.fdn.fr ([80.67.169.18]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 02 Dec 2010 00:13:21 +0100 Original-Received: from ludo by yoda.fdn.fr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 02 Dec 2010 00:13:21 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 35 Original-X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: yoda.fdn.fr X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 12 Frimaire an 219 de la =?iso-8859-1?Q?R=E9volution?= X-PGP-Key-ID: 0xEA52ECF4 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 83C4 F8E5 10A3 3B4C 5BEA D15D 77DD 95E2 EA52 ECF4 X-OS: x86_64-unknown-linux-gnu User-Agent: Gnus/5.110011 (No Gnus v0.11) Emacs/23.2 (gnu/linux) Cancel-Lock: sha1:NDFMyMurirrjVw6o+GKYZWBbh2o= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Developers list for Guile, the GNU extensibility library" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Errors-To: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.devel:11227 Archived-At: Hello there! Andy Wingo writes: > On Sat 27 Nov 2010 01:08, Andreas Rottmann writes: > >> to not lose current functionality, `print-exception' and exception >> printer procedures would need a `frame' argument as well, right? > > I guess. I never liked that, though; sounds like a needless tangling of > concerns. What does having the frame give us? Just source, or the > function name, or what? It seems like a message about the context in > which the error occurred could just as well come before the error is > printed out. > > What do you think? What does Ludovic think? :) I don’t think, actually. :-) Well, at first I thought exception printers could be nice. Currently, there’s a single exception printer, which makes assumptions about the arguments to ‘throw’. Namely, it expects (throw KEY FUNC FORMAT-STRING FORMAT-ARG ...), or something like that. When that is honored, exceptions are displayed in a human-readable way, otherwise they are (very) badly printed, which could be improved. OTOH, exceptions are a programming mechanism, not a UI mechanism, so one could argue that it’s up to the application to define how to present exceptions to the user. I think I’m slightly skeptical about system-wide exception printers because of this, and also because system-wide settings are evil. Thanks, Ludo’.