From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Jean Louis Newsgroups: gmane.emacs.help Subject: Re: [External] : Re: operations on path lists Date: Wed, 8 Feb 2023 23:09:26 +0300 Message-ID: References: <87y1pdkg6p.fsf@dataswamp.org> <87k00xje04.fsf@dataswamp.org> 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="5203"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mutt/2.2.9+54 (af2080d) (2022-11-21) Cc: "help-gnu-emacs@gnu.org" To: Drew Adams Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Wed Feb 08 21:36:17 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 1pPrAv-00018w-FL for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 08 Feb 2023 21:36:17 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pPrAK-0002so-Ci; Wed, 08 Feb 2023 15:35:40 -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 1pPrAI-0002rB-7m for help-gnu-emacs@gnu.org; Wed, 08 Feb 2023 15:35:38 -0500 Original-Received: from stw1.rcdrun.com ([217.170.207.13]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pPrAG-0006Qt-DZ for help-gnu-emacs@gnu.org; Wed, 08 Feb 2023 15:35:37 -0500 Original-Received: from localhost ([::ffff:197.239.14.90]) (AUTH: PLAIN admin, TLS: TLS1.3,256bits,ECDHE_RSA_AES_256_GCM_SHA384) by stw1.rcdrun.com with ESMTPSA id 0000000000103950.0000000063E40799.00005025; Wed, 08 Feb 2023 13:35:36 -0700 Mail-Followup-To: Drew Adams , "help-gnu-emacs@gnu.org" Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=217.170.207.13; envelope-from=bugs@gnu.support; helo=stw1.rcdrun.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham 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:142659 Archived-At: > > Let us look at `when' little: > > > > - you place `when' when you need `nil' as last resort The above I was thinking 💭, maybe by mistake, that I am answering to Swedish friend. > I don't. I do just the opposite. I use `when' and `unless' only > when the code doesn't use/depend on the return value. (I'm guessing > that's what you meant by needing nil as a last resort, though they > always return nil.) Thanks, I got your thinking, I like when I enter in your mind with such details, thanks much. What interesting stuff goes on over thousands of miles of distance. Yes, I know those return nil. You got my idea, thanks. > Before Elisp borrowed `when' and `unless' from other Lisps > (e.g. Common Lisp), the idiom, especially for a single condition, > was to use `or' in (or condition do-something) instead of `unless', > and likewise for `and' and `when'. That that, usually at top level > in a function body. I still have some of those `or' sexps, as does > standard Emacs code. Okay, I get the history, thanks. > > - without parenthesis highlighting sometimes it becomes very difficult > > to understand what did `if' author intended to say? > > I don't grok that. With `cond' I can see, usually, what is meant with the condition, as it is at least to me better structured than `if', as complexity of code requires me to count parenthesis or be very careful to understand which expression belong to which part of `if' or some `if` that follows up. With parenthesis highlighting that is helped better. > But then, I don't use `if' unless there are both a then and an else > part. I take the time to rewrite, yes, as needed, to communicate to > myself (as reader) just what the code means to do. Yes, it is good to communicate to oneself over periods of time, I forgot already what I was doing back in time, sometimes I study my program to find out what did I mean with it. -- Jean Take action in Free Software Foundation campaigns: https://www.fsf.org/campaigns In support of Richard M. Stallman https://stallmansupport.org/