From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Newsgroups: gmane.emacs.bugs Subject: bug#47677: [PATCH] condition-case success continuation Date: Sat, 24 Apr 2021 19:02:07 +0200 Message-ID: References: <219007D9-0FD0-4AC2-A8B0-24A0FC277AE8@acm.org> <87lf9nzy48.fsf@gnus.org> <87F315E7-7F8A-46C5-A71B-F090F067D0B8@acm.org> <87sg3uskgt.fsf@gnus.org> <87zgy1qkni.fsf@gnus.org> Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.17\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="7469"; mail-complaints-to="usenet@ciao.gmane.io" Cc: larsi@gnus.org, stefan@marxist.se, monnier@iro.umontreal.ca, 47677@debbugs.gnu.org To: Richard Stallman Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sat Apr 24 19:03:25 2021 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1laLgi-0001dQ-Jo for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 24 Apr 2021 19:03:24 +0200 Original-Received: from localhost ([::1]:44748 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1laLgh-000272-Md for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 24 Apr 2021 13:03:23 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:60126) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1laLgM-00026T-UJ for bug-gnu-emacs@gnu.org; Sat, 24 Apr 2021 13:03:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:58070) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1laLgM-0001WV-9m for bug-gnu-emacs@gnu.org; Sat, 24 Apr 2021 13:03:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1laLgM-00027A-7Z for bug-gnu-emacs@gnu.org; Sat, 24 Apr 2021 13:03:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 24 Apr 2021 17:03:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 47677 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: patch Original-Received: via spool by 47677-submit@debbugs.gnu.org id=B47677.16192837738104 (code B ref 47677); Sat, 24 Apr 2021 17:03:02 +0000 Original-Received: (at 47677) by debbugs.gnu.org; 24 Apr 2021 17:02:53 +0000 Original-Received: from localhost ([127.0.0.1]:41382 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1laLgD-00026d-46 for submit@debbugs.gnu.org; Sat, 24 Apr 2021 13:02:53 -0400 Original-Received: from mail1433c50.megamailservers.eu ([91.136.14.33]:50364 helo=mail263c50.megamailservers.eu) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1laLgB-00026Q-Iy for 47677@debbugs.gnu.org; Sat, 24 Apr 2021 13:02:52 -0400 X-Authenticated-User: mattiase@bredband.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megamailservers.eu; s=maildub; t=1619283730; bh=SLyn4X6Bpul+RTpV0XEKgG+PdQs8BCKRLsC0FG96ZaI=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=cS072YZSA7VfYFjwFLXaflZUzJ4LkKOtlAPXOhPjxlAsA6S2/GnnpsPU5x120ej6Z GhEbPtuy7XAzAxNPCc/fRiAUv8oPw10UmcnjrNhhEyNG8qA809fRMAYP4heHdU+dCY ESK2nNyhER7X8w07N6PVIJMf5V/88GfRTjWGBC5s= Feedback-ID: mattiase@acm.or Original-Received: from [192.168.0.4] (c188-150-171-71.bredband.comhem.se [188.150.171.71]) (authenticated bits=0) by mail263c50.megamailservers.eu (8.14.9/8.13.1) with ESMTP id 13OH27Uq002449; Sat, 24 Apr 2021 17:02:09 +0000 In-Reply-To: X-Mailer: Apple Mail (2.3445.104.17) X-CTCH-RefID: str=0001.0A742F20.60844F12.004C, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0 X-CTCH-VOD: Unknown X-CTCH-Spam: Unknown X-CTCH-Score: 0.000 X-CTCH-Flags: 0 X-CTCH-ScoreCust: 0.000 X-CSC: 0 X-CHA: v=2.3 cv=LMMYv6e9 c=1 sm=1 tr=0 a=SF+I6pRkHZhrawxbOkkvaA==:117 a=SF+I6pRkHZhrawxbOkkvaA==:17 a=kj9zAlcOel0A:10 a=M51BFTxLslgA:10 a=mDV3o1hIAAAA:8 a=8-HhnExR7SEaPYK0n_8A:9 a=CjuIK1q_8ugA:10 a=_FVE-zBwftR9WsbkzFJk:22 X-Origin-Country: SE X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list 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-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:204814 Archived-At: 23 apr. 2021 kl. 06.18 skrev Richard Stallman : > catch and throw are ok > as they are, and we should leave them alone. And so we do! All we do here is to fill a few gaps in the system, but if = you don't feel the need for it then you can just ignore that the new = construct exist. See the previous discussion for examples, but your code is also a good = illustration: > (if (catch 'foo > (prog1 nil > ...do stuff...)) ;; use (throw 'foo t) to exit > do-if-throw > do-if-no-throw) Here the throw transmits no useful value at all; if it did, this value = would have to be restricted in some way, such as being non-nil. The Lisp = implementation knows very well whether a throw occurred or not, so we = can expose that information instead of having the user hack around the = limitation. Common uses of catch/throw include early exits from deep searches when a = match is found, and then it is useful that the thrown value is = unrestricted. Conversely, when `throw` is used to indicate a failure, it = is useful to have the normal return value unrestricted. The patch does not include the required documentation changes; naturally = that will be remedied.