From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Michael Heerdegen Newsgroups: gmane.emacs.devel Subject: Re: Why is FUNC in cl-callf not allowed to be an expression? Date: Fri, 10 May 2019 17:18:22 +0200 Message-ID: <87r2961gox.fsf@web.de> References: <874l631ek1.fsf@web.de> <87pnoqtuhm.fsf@web.de> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="155400"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) Cc: emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri May 10 17:22:46 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hP7M9-000eGg-Rl for ged-emacs-devel@m.gmane.org; Fri, 10 May 2019 17:22:42 +0200 Original-Received: from localhost ([127.0.0.1]:44995 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hP7M8-0000AW-NV for ged-emacs-devel@m.gmane.org; Fri, 10 May 2019 11:22:40 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:55651) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hP7IA-0006YM-Gc for emacs-devel@gnu.org; Fri, 10 May 2019 11:18:35 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hP7I9-0006nF-Ge for emacs-devel@gnu.org; Fri, 10 May 2019 11:18:34 -0400 Original-Received: from mout.web.de ([212.227.17.11]:45273) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hP7I9-0006lt-68 for emacs-devel@gnu.org; Fri, 10 May 2019 11:18:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1557501503; bh=RWdoUUm1+Mi4oNQ1Su11Nfh/AGRVVsbjgoYJHewzI/8=; h=X-UI-Sender-Class:From:To:Cc:Subject:References:Date:In-Reply-To; b=MSWgDVypzyZOsmRYpx5QJab1zi4hiaRScaXpjQ41yfhQ9T9bJ19hdJcmTDCE0Rmir yHxvMmKTjuO54FtmnkHZ8BWOTqzNwqiZJBxfbHPSLhkhslKlps0Kkpm54m7hgiKrMO ffLjdcW30VmoH0iwd0AWukt6hVRomFWfNBmgtkng= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Original-Received: from drachen.dragon ([88.66.186.107]) by smtp.web.de (mrweb101 [213.165.67.124]) with ESMTPSA (Nemesis) id 0MJkt6-1hO0pH22Oy-0019lz; Fri, 10 May 2019 17:18:23 +0200 In-Reply-To: (Stefan Monnier's message of "Fri, 10 May 2019 10:22:31 -0400") X-Provags-ID: V03:K1:SgVWIWhOK0biQzXx6F0SFa9P3TCr4x5h+7om4J+514IJ9oWNj52 VY7xUHohwYtRK4eZsfsZhUYj1qrL4Kzh8tW3+piL3ZzHFi170UyZovcDHJHyjvYTr33rpCU WY09t42rHvE59V/RH3lZuYR+GgsNdIxdBjobpV1eLUGUTIf2QVexz8aS30GJHbnrSQpWiy6 XSeG47+un3hQhwPPyLgEA== X-UI-Out-Filterresults: notjunk:1;V03:K0:0VJJ2oXe5y4=:dCel4nCRs8GtjAp+hwE6V+ l0YILPhHkjKOIr0DTI9c7LDON0FVFpvnL0N4Rmz38GIZQkX0Tj9AF4CF5gF7yExN3lQ16q6Ht mRsy+2aBB4HYgaSrQUMqm70nQxNcvctzSHGL/Syt8WoNzLt+yMKbcX/ZBtmBG5kr307u8VIqJ iaoagudsmVviFsfa/l1C6VYfhpB0QkQpTPMWOlyKm1vfPU3SQIKwYrJfMakvtq0V/oiP6lhzu dy2hVXaoMPdbELkHG42dMOcO6BST+XzT1fA2lKFO0DTfNGQx13HYYamLA7xaC9sKs14KV6aAH XRR3SaYZ2WuyynQKCjhUqGu3enspk7TiO52XC1+k0uo/5e7iH13a2BPyjrzxiCCqBZM2hDTmL TFM19gvFlL1AKQoDjFXn6rlPS/lbPKdBCb2gHz25FVD9NnssHVuiT4S4mRWo/eRvNBRir3MrN mlCwudIpiZmCsp6wwnBMoVgQVD+fcSVo2TtIePKSizif1f9TVLI1ALGmlR31cz/PNkNPf2fms JQEyONMOESVILWj49IaI5RlKEHp2/q+dVSAOC0XYwA94g9iGfjMXftAbZHnnkEFi0WpOI/vDj htZ6m15OlpcE4aHDlr3oIawis+DkBS1aW5WKMIV07g2YqhGkRtQpBBagv6J4mhEu1MW1UHa5h L1Egp1M4sf+7PC5DnlUg7R8bWRdllnqWQ9ROTakrRONyWmD6PPpiAOV39N6vuujypPdszRnEE RUzdZIFvfTtirKdL3APPa0bQZOhEY/IppULf8Eaa0gEkKx2i/dUqv89cJhkKQROkVnp/ICtm X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 212.227.17.11 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:236385 Archived-At: Stefan Monnier writes: > > Now that I look at it again, I guess an "anamorphic" version would be > > probably more obvious: > > > > (gv-modify (nth i l) > > (append head it (cdr x))) I guess I would rather like it with explicit naming: (defmacro gv-modify (binding call) (declare (indent 1)) (pcase-let ((`(,var ,place) binding)) (gv-letplace (getter setter) place (funcall setter `(let ((,var ,getter)) ,call))))) Example: (let ((l '(x ((2 3))))) (gv-modify (plc (car (cadr l))) (append '(0 1) plc '(4 5))) l) =3D> (x ((0 1 2 3 4 5))) > And I see it solves another downside of (gv-callf N EXP), which is that = in > > (gv-callf 2 (append HEAD (nth INDEX LIST) TAIL)) > > the evaluation order will actually end up being > > INDEX; LIST; HEAD; TAIL > > which is counter-intuitive. The disadvantage is that the `append' call looks a bit pulled apart, but I think it would be ok for me. Michael.