From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Emanuel Berg Newsgroups: gmane.emacs.help Subject: Re: Closures - do you understand them well? Date: Wed, 18 Jan 2023 13:08:53 +0100 Message-ID: <87y1q0xcx6.fsf@dataswamp.org> References: <87lenh7vrn.fsf@web.de> <87lenh7k9m.fsf@ericabrahamsen.net> <875yelpqh9.fsf@web.de> <87v8mlo4ud.fsf@web.de> <87zgbwjzc6.fsf@ericabrahamsen.net> <87pmcstm5r.fsf@web.de> <87bko9dbow.fsf@ericabrahamsen.net> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="30853"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:mrXdKLxkD2/HBFU7Ch2tKmDyZCo= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Thu Jan 19 12:41:19 2023 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 1pITIF-0007nC-Go for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 19 Jan 2023 12:41:19 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pITI2-0003zh-5p; Thu, 19 Jan 2023 06:41:06 -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 1pI7Fb-000124-7H for help-gnu-emacs@gnu.org; Wed, 18 Jan 2023 07:09:09 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pI7FZ-00088O-GL for help-gnu-emacs@gnu.org; Wed, 18 Jan 2023 07:09:06 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1pI7FV-0001FZ-FF for help-gnu-emacs@gnu.org; Wed, 18 Jan 2023 13:09:01 +0100 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: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Thu, 19 Jan 2023 06:41:05 -0500 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:142407 Archived-At: Eric Abrahamsen wrote: > But I've always found multiple layers of indirection > confusing (recursion/TCO and nested macros included) TCO = Tail-Call Optimization, so you can use recursion without blowing up the stack ... But recursion isn't confusing, it makes for elegant/textbook programs, it's not really a layer of indirection, is it? Nested macros tho are like the definition of that (extra layer/indirection) since instead of you program -> a program -> that does stuff it is you program -> a program -> that expands into a program -> that does stuff It makes the programming language programmable ... -- underground experts united https://dataswamp.org/~incal