From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: =?utf-8?Q?=C3=93scar_Fuentes?= Newsgroups: gmane.emacs.help Subject: Re: (*) -> 1 Date: Thu, 19 Jan 2023 17:51:55 +0100 Message-ID: <87o7qu8o2c.fsf@telefonica.net> References: <87y1q1kvdm.fsf@web.de> <87h6wpkrlq.fsf@web.de> <87zgahj7h3.fsf@web.de> <87cz7c9c9e.fsf@telefonica.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="26096"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:TKeAzuf0s2LehikkTnjQLeQ/DWo= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Thu Jan 19 17:52:53 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 1pIY9i-0006Jm-VM for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 19 Jan 2023 17:52:50 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pIY98-0006u7-I9; Thu, 19 Jan 2023 11:52:14 -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 1pIY94-0006tp-GD for help-gnu-emacs@gnu.org; Thu, 19 Jan 2023 11:52:10 -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 1pIY91-0000w2-5A for help-gnu-emacs@gnu.org; Thu, 19 Jan 2023 11:52:08 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1pIY8y-0005Dx-Lz for help-gnu-emacs@gnu.org; Thu, 19 Jan 2023 17:52:04 +0100 X-Injected-Via-Gmane: http://gmane.org/ 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-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:142434 Archived-At: Jean Louis writes: > * Óscar Fuentes [2023-01-18 16:58]: >> Jean Louis writes: >> >> > * Michael Heerdegen [2023-01-17 22:20]: >> >> The question of use is a valid one, we missed to answer it yet. It >> >> wasn't clear to me that this was part of what you are asking for. >> > >> > Yes, that one. >> > >> > Why authors decided to have (*) ➜ 1 which in case of me who could >> > delete some argument like from (* tonnes quantity) I could by mistake >> > delete "tonnes and quantity" and result of (*) would not be detected >> > because there is no error >> >> Throwing an error on this case is a reasonable possibility for the >> language designers, but instead they decided to extend * to zero and one >> arguments. Why? because it is convenient, because it makes possible to >> do things like (apply '* some-list) without caring about how many >> elements some-list has, which is handy when some-list comes from a place >> you don't control. > > That explanation sounds like neglect in programming. That's your personal opinion. Quite a few programmers think that not using strict strongly-typed, statically-typed languages is irresponsible, and see, here we are dicussing Lisp. BTW, do you consider support for more than two arguments on + and * also a neglect in programming? > I have mentioned > that PicoLisp can `apply' with (*) yielding NIL. Try it out. The first thing written in PicoLisp's home page is: PicoLisp is quite different from other Lisps. So be wary when taking PicoLisp's behavior as a comparison point when discussing other Lisp implementations. > ~$ pil > : (*) > -> NIL > : (+) > -> NIL > : (apply '* '(2 3)) > -> 6 What's the output of (apply '* '()) in PicoLisp? > it means it is not really to give relief to other functions. And there > is nothing wrong for apply to yell the error when arguments are > missing to the function. > > If you have some reference to that reasoning that (*) is related to > `apply' from language designer, let me know. I have no such references, nor I need them: it is immediately obvious to me. BTW, I'll say this for the last time: In Elisp, + is not the binary addition operator. It is the summation operator (aka Σ) for finite sequences. In Elisp, * is not the binary multiplication operator. It is the product operator (aka Π) for finite sequences. Once you internalize this, things will be clearer.