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: [External] : `let' vs `let*' (was: Re: How do I pass a variable defined in a wrapping let, to a lambda?) Date: Wed, 16 Mar 2022 01:25:34 +0100 Message-ID: <87mthq216p.fsf@zoho.eu> References: <87k0d03vaw.fsf@ericabrahamsen.net> <8735joc5of.fsf@web.de> <87r177rjzn.fsf@zoho.eu> <874k40iqmd.fsf_-_@zoho.eu> Reply-To: Emanuel Berg 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="26171"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:VgPH3OFKZLxU5NTK1a3mPPULHVs= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Wed Mar 16 03:02:36 2022 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 1nUIzj-0006YO-41 for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 16 Mar 2022 03:02:35 +0100 Original-Received: from localhost ([::1]:53108 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nUIzh-0001Cl-QJ for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 15 Mar 2022 22:02:33 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:34578) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nUHU2-000315-4X for help-gnu-emacs@gnu.org; Tue, 15 Mar 2022 20:25:46 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:59272) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nUHU0-0007mi-2t for help-gnu-emacs@gnu.org; Tue, 15 Mar 2022 20:25:45 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1nUHTx-0003M8-W9 for help-gnu-emacs@gnu.org; Wed, 16 Mar 2022 01:25:41 +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, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Tue, 15 Mar 2022 21:59:48 -0400 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" Xref: news.gmane.io gmane.emacs.help:136605 Archived-At: Re: [External] : `let' vs `let*' (was: Re: How do I pass a variable defined in a wrapping let, to a lambda?) tomas wrote: > (setq a 42) > (setq b 43) > (let ((a b) > (b a)) > (list a b)) > > => (43 42) > > [...] And one could ask oneself whether it's wise to shadow > variables from the outer environment And the answer is: it is foolish. So, examples are academic, and in practice it doesn't make sense? No: 1. Let `let' be `let*'; and 2. let let* be an alias to `let'. So then we would have: [f -> g denotes (defalias 'f #'g) ] obsolete/remove ↓ ↓ dlet* -> dlet ↓ let* -> let lexical-let -> llet* -> llet -> let _or_ slet [note] slet* -> slet [note] Both make sense: `let' by convention, and intuitive that the well-known let under static/lexical scope is llet (the lexical let); OHOH it could be alias to slet just as well to uphold consistency with the others, as dlet means ONLY dynamic/special and slet means ONLY static/lexical, so llet should perhaps then mean only static/lexical as well which then would be = slet. `let' is/can be static/lexical AND/OR dynamical/special, the other two means one for all dynamic/special (dlet) and one for all static/lexical (slet). The one. The mix. The other. That's All Folks! -- underground experts united https://dataswamp.org/~incal