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: How do I pass a variable defined in a wrapping let, to a lambda? Date: Sat, 12 Mar 2022 01:47:55 +0100 Message-ID: <878rtgro78.fsf@zoho.eu> References: <87sfrorqh2.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="24073"; 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: sha1:00pud9eG4naZHijK9GlyhJtI0pQ= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sat Mar 12 01:57:54 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 1nSq4v-00060c-Pq for geh-help-gnu-emacs@m.gmane-mx.org; Sat, 12 Mar 2022 01:57:53 +0100 Original-Received: from localhost ([::1]:54470 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nSq4u-00051p-7x for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 11 Mar 2022 19:57:52 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:33630) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nSpxO-00048g-Rx for help-gnu-emacs@gnu.org; Fri, 11 Mar 2022 19:50:08 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]:41076) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nSpxN-00038z-7g for help-gnu-emacs@gnu.org; Fri, 11 Mar 2022 19:50:06 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1nSpxK-0007Bc-Jj for help-gnu-emacs@gnu.org; Sat, 12 Mar 2022 01:50:02 +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: Fri, 11 Mar 2022 19:57:15 -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" Xref: news.gmane.io gmane.emacs.help:136469 Archived-At: With static/lexical scope, you get the closure: ;;; -*- lexical-binding: t -*- ;; ;; this file: ;; https://dataswamp.org/~incal/emacs-init/geh.el (defun add-one-f (term) (let ((tm term)) (lambda () (1+ tm)) )) ;; (funcall (add-one-f 2)) ; 3 ;; (add-one-f 2) ; (closure ((tm . 2) (term . 2) t) nil (1+ tm)) But with dynamic/special scope, you get only the lambda: ;; this file: ;; https://dataswamp.org/~incal/emacs-init/geh-dynamic.el (defun add-two-f (term) (let ((tm term)) (lambda () (+ 2 tm)) )) ;; (funcall (add-two-f 2)) ; Symbol’s value as variable is void: tm ;; (add-two-f 2) ; (lambda nil (+ 2 tm)) -- underground experts united https://dataswamp.org/~incal