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: `let' vs `let*' (was: Re: How do I pass a variable defined in a wrapping let, to a lambda?) Date: Tue, 15 Mar 2022 09:30:29 +0100 Message-ID: <87fsnj39ei.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="15947"; 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:wBwml+p/F0thOgveqptZeiUkAqw= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Mar 15 16:43:25 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 1nU9KX-0003uY-Gv for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 15 Mar 2022 16:43:25 +0100 Original-Received: from localhost ([::1]:53580 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nU9KW-0004Eb-Le for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 15 Mar 2022 11:43:24 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:50790) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nU2Zo-0005Ti-Sq for help-gnu-emacs@gnu.org; Tue, 15 Mar 2022 04:30:45 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:47662) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nU2Zk-0002uO-EY for help-gnu-emacs@gnu.org; Tue, 15 Mar 2022 04:30:44 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1nU2Zi-0007x5-0t for help-gnu-emacs@gnu.org; Tue, 15 Mar 2022 09:30:38 +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 11:35:45 -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:136586 Archived-At: Jean Louis wrote: >> As for `let' vs `let*' in theory `let' is parallel and >> `let*' sequential but in practice `let*' allows references >> back to its own bindings, so it is recursive `let' if you >> will, and `let' isn't ... > > In the `dlet' discussion, well... I see it so, dlet is > creating dynamically bound variables, and thus they should > be available to all variables inside of `dlet" > > (dlet ((first-var 1) > (second-var first-var)) > second-var) > > second-var should be equal to first var Well, the discussion can go both ways ... (defvar first-var) (setq first-var 0) (dlet ((first-var 1) (second-var first-var)) (list second-var first-var)) ; (0 1) > but developer Mattias Engdegård, he changed it for the > reason that dlet is not dlet* > >> commit b72f88518b89560accf740a4548368863e6238e0 >> Author: Mattias Engdegård >> Date: Sun Aug 1 17:05:48 2021 +0200 >> >> * Make dlet work like let, not let* >> >> * Change `dlet` so that it has binding semantics like `let` because that >> * is what a user would expect and it allows a corresponding `dlet*` to >> be added later should the need arise. Fortunately the change has no >> effect where it is currently used. > > That is what user would expect. But that is not what I as > user expect. And nobody of other users complained on that, > though the definition of dlet is changed. If there are `let' and `let*' I think it makes sense with `dlet' and dlet*, and slet/llet and slet*/llet*. Don't know how much sense `let' and `let*' do tho. Maybe someone is working on the/a true parallel `let' as we speak ... well, keep it then I guess :) > dlet is described with: Like ‘let’ but using > dynamic scoping. Poor docstring. Because `let' can do dynamic/special variables even under static/lexical scope. Maybe one could get away with just adding the word ALWAYS somewhere ... -- underground experts united https://dataswamp.org/~incal