From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings Newsgroups: gmane.emacs.bugs Subject: bug#47677: [PATCH] condition-case success continuation Date: Mon, 26 Apr 2021 21:57:46 +0000 Message-ID: <770e344122f2eed113c2@heytings.org> References: <219007D9-0FD0-4AC2-A8B0-24A0FC277AE8@acm.org> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="33040"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 47677@debbugs.gnu.org To: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Mon Apr 26 23:58:11 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 1lb9F5-0008T8-4f for geb-bug-gnu-emacs@m.gmane-mx.org; Mon, 26 Apr 2021 23:58:11 +0200 Original-Received: from localhost ([::1]:49116 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lb9F4-0005ZK-8D for geb-bug-gnu-emacs@m.gmane-mx.org; Mon, 26 Apr 2021 17:58:10 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:52776) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lb9Ew-0005Ys-P6 for bug-gnu-emacs@gnu.org; Mon, 26 Apr 2021 17:58:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:35888) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lb9Ew-0001xJ-HV for bug-gnu-emacs@gnu.org; Mon, 26 Apr 2021 17:58:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1lb9Ew-0007cK-Em for bug-gnu-emacs@gnu.org; Mon, 26 Apr 2021 17:58:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Gregory Heytings Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 26 Apr 2021 21:58:02 +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=B47677.161947427129264 (code B ref 47677); Mon, 26 Apr 2021 21:58:02 +0000 Original-Received: (at 47677) by debbugs.gnu.org; 26 Apr 2021 21:57:51 +0000 Original-Received: from localhost ([127.0.0.1]:47434 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lb9El-0007bw-3S for submit@debbugs.gnu.org; Mon, 26 Apr 2021 17:57:51 -0400 Original-Received: from heytings.org ([95.142.160.155]:54474) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lb9Ei-0007bl-6h for 47677@debbugs.gnu.org; Mon, 26 Apr 2021 17:57:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heytings.org; s=20210101; t=1619474266; bh=1gvnAzWemSTb579lSHM+iQMPgr/Q4E3srQnMJCLuYOs=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:From; b=f6xDaa8+OnuprVFYHcIwtnvxqV6IC8iKLZf4VllG3/HqimUDnstBD5Anh5EHCfoQ/ VwVRqbfytwv5SSHNOOQmZd8+xqACq/JqN4wjzP93sd7gwIOtOFqHpo3kOufqBcLJnE vFFVS67pv4tudOILqkSVsWWZAWsxN3d43VNXlWye0s2ejvcGuj5fgFtRQBnC+KkBuY StUM2x7o5cug3i0mGtCzP3Vv0USL7EoCDl3asc7SmVC0r6R+y+0C6tYikm1v1mALfE WTMfP+mM9a3nj2jKKzvJE6r3Wk6TDGPsr9/d7UhV2I0oCyJQx0NvrWoOznzGX8KZHK FGZZiNSnBP54Q== In-Reply-To: <219007D9-0FD0-4AC2-A8B0-24A0FC277AE8@acm.org> 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:204977 Archived-At: > > This patch adds the condition-case handler syntax > > (:success BODY) > > for code executed when the protected form terminates without error. BODY > is then executed with the variable bound to the result of the protected > form, and the result of BODY is then the value of the condition-case > form as usual. > > This plugs an annoying hole in elisp: there hasn't been any direct > access to the success continuation > Would a macro not be enough to cover that particular programming pattern? E.g. something like: (defmacro success-case (value action continuation &rest handlers) `(catch 'success-case-fail ((lambda (,value) ,continuation) (catch 'success-case-success (throw 'success-case-fail (condition-case ,value (throw 'success-case-success ,action) ,@handlers)))))) With this macro you can write for example: (success-case result (read buffer) (use result) (end-of-file 'eof)) which is IMO even more concise and elegant.