From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Why is FUNC in cl-callf not allowed to be an expression? Date: Fri, 10 May 2019 10:22:31 -0400 Message-ID: References: <874l631ek1.fsf@web.de> <87pnoqtuhm.fsf@web.de> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="137798"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri May 10 16:26:54 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 1hP6U9-000ZgK-RQ for ged-emacs-devel@m.gmane.org; Fri, 10 May 2019 16:26:53 +0200 Original-Received: from localhost ([127.0.0.1]:44267 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hP6U8-0001bq-QV for ged-emacs-devel@m.gmane.org; Fri, 10 May 2019 10:26:52 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:45161) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hP6SP-0000LN-PQ for emacs-devel@gnu.org; Fri, 10 May 2019 10:25:06 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hP6SO-0001J9-HL for emacs-devel@gnu.org; Fri, 10 May 2019 10:25:05 -0400 Original-Received: from [195.159.176.226] (port=60702 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hP6SO-0001IE-Ac for emacs-devel@gnu.org; Fri, 10 May 2019 10:25:04 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.89) (envelope-from ) id 1hP6SM-000XR8-8d for emacs-devel@gnu.org; Fri, 10 May 2019 16:25:02 +0200 X-Injected-Via-Gmane: http://gmane.org/ Cancel-Lock: sha1:Qv+nuPOdctnQBG32iimbAlhoanY= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 195.159.176.226 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:236377 Archived-At: > 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))) 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. Stefan