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: named-let Date: Sat, 09 Jan 2021 16:48:36 -0500 Message-ID: References: <20210109085840.GA20537@tuxteam.de> <871reu85cr.fsf@fastmail.fm> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="2463"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: tomas@tuxteam.de, emacs-devel@gnu.org To: Joost Kremers Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Jan 09 22:49:27 2021 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 1kyM6x-0000Yk-90 for ged-emacs-devel@m.gmane-mx.org; Sat, 09 Jan 2021 22:49:27 +0100 Original-Received: from localhost ([::1]:48234 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kyM6w-00080E-BH for ged-emacs-devel@m.gmane-mx.org; Sat, 09 Jan 2021 16:49:26 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:52726) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kyM6G-0007aC-Ln for emacs-devel@gnu.org; Sat, 09 Jan 2021 16:48:44 -0500 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:39812) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kyM6E-0008Vd-3J for emacs-devel@gnu.org; Sat, 09 Jan 2021 16:48:43 -0500 Original-Received: from pmg2.iro.umontreal.ca (localhost.localdomain [127.0.0.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id E6FC080E43; Sat, 9 Jan 2021 16:48:39 -0500 (EST) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id 96AF58064E; Sat, 9 Jan 2021 16:48:38 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1610228918; bh=k0FvPo7deqRLtpL3wyUK6HgT7b3bpaZsZhortZ+gaVY=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=dgdL0lVo8O5iyFrcpq2piXZ5fGlwCVPFezea1NXdZ/Ty84JggstWyb0QU20vFAy6o UJnQ95KoLbeVUchK8kWRqhAOjkqnvl2NiG0oQzFvkOEPXn/Qm1fxe+P2rIfnR9XrrF C6FkeJ71LHU8Pa5Wvtv0FETN3NHJPFABu/aWIExSnpj8c0Jtb03Ivem7SFIVO5Vxk7 MyqaQPx1AhdSvpQus3X+5kERJrZradIpqBqM27hx61UD5GzkL5C5LGJeHbh9yFzIpX +401ouTfRMX4fWz9QULCxI9S452b97hGfOt2iUzpJhORJPk+Rdsvl74/ANNYWEZwRB ECDGdTkUbuABw== Original-Received: from alfajor (unknown [45.72.224.181]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id 623991204A6; Sat, 9 Jan 2021 16:48:38 -0500 (EST) In-Reply-To: <871reu85cr.fsf@fastmail.fm> (Joost Kremers's message of "Sat, 09 Jan 2021 17:01:54 +0100") 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 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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" Xref: news.gmane.io gmane.emacs.devel:262822 Archived-At: >> (Back on topic: I grew some affection for the named let >> from the Scheme/Guile side, so thanks for that, too) > Hmpf, I prefer loop/recur... *grumblegrumble* Well, (defmacro loop (&rest r) `(named-let recur . ,r)) does the trick AFAIK, except that it won't signal an error for uses of `recur` which aren't recognized as tail-calls. It would be easy to make a replacement of `cl-labels` which signals an error if the recursice calls aren't recognized as tail-calls (the current code already tests for it, but only in order to optimize the `letrec` into a `let*` rather than to signal an error). Stefan