From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Emanuel Berg via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: How to create a higher order function? Date: Tue, 21 Sep 2021 06:50:45 +0200 Message-ID: <87o88m8rbu.fsf@zoho.eu> References: <87k0jawotx.fsf@mbork.pl> Reply-To: Emanuel Berg Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="17774"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:X4IK7xjZ0tazmlRlks3JN30YpEQ= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Sep 21 06:51:16 2021 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 1mSXkR-0004M3-UE for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 21 Sep 2021 06:51:15 +0200 Original-Received: from localhost ([::1]:43612 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mSXkP-0007Gh-M3 for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 21 Sep 2021 00:51:13 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:60144) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mSXk8-0007GZ-Hv for help-gnu-emacs@gnu.org; Tue, 21 Sep 2021 00:50:56 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:35636) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mSXk6-0000TS-Q7 for help-gnu-emacs@gnu.org; Tue, 21 Sep 2021 00:50:56 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1mSXk4-0003sM-A7 for help-gnu-emacs@gnu.org; Tue, 21 Sep 2021 06:50:52 +0200 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: help-gnu-emacs@gnu.org Mail-Copies-To: never Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 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" Xref: news.gmane.io gmane.emacs.help:133119 Archived-At: Marcin Borkowski wrote: > ;;; -*- lexical-binding: nil; -*- > (defun negate (fun) > "Return a function returning the logical opposite of FUN." > `(lambda (&rest args) > (not (apply ,(symbol-function fun) args)))) > > It seems to work fine, even if it's a bit complicated. symbol -> list If you want a symbol to symbol mapping you can use `make-symbol' and then `setf' on the `symbol-function' of the argument symbol - maybe ... -- underground experts united https://dataswamp.org/~incal