From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Michael Heerdegen Newsgroups: gmane.emacs.help Subject: Re: Closures - do you understand them well? Date: Mon, 12 Dec 2022 02:18:04 +0100 Message-ID: <87pmcpo1wz.fsf@web.de> References: <87lenh7vrn.fsf@web.de> <87tu25d77o.fsf@gnu.org> <87h6y5pt8k.fsf@web.de> <87bkodpqnk.fsf@web.de> <87k030tlfh.fsf@web.de> <87ilike1l8.fsf@gnu.org> <87cz8suv92.fsf@dataswamp.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="2174"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: help-gnu-emacs@gnu.org To: Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Mon Dec 12 02:18:55 2022 Return-path: Envelope-to: geh-help-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 1p4XT4-0000LS-AO for geh-help-gnu-emacs@m.gmane-mx.org; Mon, 12 Dec 2022 02:18:54 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p4XSP-0004dW-9g; Sun, 11 Dec 2022 20:18:13 -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 1p4XSN-0004dJ-MS for help-gnu-emacs@gnu.org; Sun, 11 Dec 2022 20:18:11 -0500 Original-Received: from mout.web.de ([212.227.15.4]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p4XSL-0005Hh-4q for help-gnu-emacs@gnu.org; Sun, 11 Dec 2022 20:18:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=s29768273; t=1670807885; bh=7OWH25MMskr4c4p8vNLUYPkdpJD8oBADY7JwRRRYzlw=; h=X-UI-Sender-Class:From:To:Cc:Subject:In-Reply-To:References:Date; b=VVXkYWYKI86IcwKxXlfeDgS/RC0IevxP6IEfuXZHHeLdtCVraW7xSYhDtQv9G1a8g pnFTAz42u5tQFPagcavDpErKyIhU/E5zZOWYnX8DXPE6JwPzMI9uBsMai5bEt5JAOw yIJiLzzXcnII91NUrRE/+JfQFTllF+z2L9isnQ9esPnInBU0zNN+k/471uma6ZSS2J MYYgzcoWjWyw27/mxSZ01fn1c0qp3itNCiH9m/Am6eoeN7kkdwEN3e9/pXxbLXi86s 9czqVKk0Eg36uV0jpICgtHjJLRC5JnU3Jot2CaJI84J5WJGQmzoRCnTO/zbUgNrXnf rWDlbAS3eWv3Q== X-UI-Sender-Class: 814a7b36-bfc1-4dae-8640-3722d8ec6cd6 Original-Received: from drachen.dragon ([92.76.229.140]) by smtp.web.de (mrweb006 [213.165.67.108]) with ESMTPSA (Nemesis) id 1MKM5z-1pN2qA0Of1-00LXk3; Mon, 12 Dec 2022 02:18:05 +0100 In-Reply-To: (tomas@tuxteam.de's message of "Sat, 10 Dec 2022 12:40:31 +0100") X-Provags-ID: V03:K1:RUXS4Yz/NTLRveWbNVOxUF+AicpXnQ3ZUy8o8pBf80r8QV3rRL6 3VnnGLpFDZ7GjxXw3NyCZR7+3YiFgLmVLx0iO/HJ9XvBHFpZLYTDoffG9DgRNx32Z77xoJo vGzYUMCIYoYQ1XgDQzINmdj5/cgAPYEgmZxd12D94cQWDlKHm0uw4zEPzG30vbwkeHzRA2o T4eUxj4WY8WUxTQQjXGzA== UI-OutboundReport: notjunk:1;M01:P0:8VeOnFQTIwE=;L2smbl1KiidIhVsYV8a/3rhpTPe lRSVCH8UTMRL17/tqfwF7RjlHZBGlZWABzG5E+CXzu2cq0vPoUOxi2LK73INjA6hywC8qCmzG bZU+72Z3H409TrjfJu1ODNb4QTGfgMO0xvPfEOZNcwBD5Qh2d5aqZaNXFHeG0ToN5rkHEK5uh RwzgDhZsBivA4zPxY7HK4vpPUNwtIhLgQmrf/L6Jg+hjjg3RxKcFtUUbrMGuvuZo9qWOjk58D 2VtZ3zvumTrJcOrinUbDobRkGr/79sr7++UJl1N4iTfumAzUNavLaL4ZlaBvkDdFChwqmhji7 zajH/a83/uOw7gVT4wJpHFm4nkYsO/fk8pGlbksYnQano0iJHNiav1iX/k3yKPjSlsHtLNuid ZbZEwBM8ZvAVDFQWAfD/Q+Zu/ZU54ex+QKE2WzCmglocu9LWzHdFpswFlyUZgFqwFHl+3Vgha 8JsGsfB2KEHhQjqlHKSm2AnvRmEo7moAIx3ynOG53a8SGfS4Ztekp/Q8YkVQtOZhV4hSwfeio 2MuarUACeKa8dvkCzJfFTwRkuch9QLO+I86zBYu1XvHTkQ5j0lHI8UFEElD1eTMksXMDADE6X hNCTB76Gr4kRMfmEiaFIb1ygXxj2mky0QsZEzVv7/gSo5tXc7SXQvgopv3zsOQVJjRAjAfljJ nhJ7UFqgIyZLEJvl8Paf4M/gN13Br3BpmnTcPO8324R2K4lJjpIk449dIEYE8RX953x+RrWrF T+l2+F1B1kFQCLD3PDPpxBhmASQPWSoXWkV3vMq8fVamVRXsgcrWQOx1wLUyscgiIqgunlzG Received-SPF: pass client-ip=212.227.15.4; envelope-from=michael_heerdegen@web.de; helo=mout.web.de X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:141654 Archived-At: writes: > > > (let ((i 0) > > > funs) > > > (while (< i 100) > > > (push `(lambda () ,i) funs) > > > (cl-incf i)) > > > (mapcar #'funcall funs)) > > > > Yes, but here there is no "new binding" exactly, rather the > > value is hard-coded onto the lambda ... > > Look closely. There is one. Just at macro expansion (aka compile) > time. ?!? The expansion of (push `(lambda () ,i) funs) is #+begin_src emacs-lisp (setq funs (cons (list 'lambda nil i) funs)) #+end_src No binding is created here, neither at compile time (where the symbol i is not touched), nor at run-time (where the value of `i` is just passed as an argument to `list'). Stefan would say that this accumulates a list of function expressions in FUNS, not a list of functions, strictly speaking. Works only because the Lisp interpreter is made to be nice to everyone. Michael.