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] : Re: Lexical vs. dynamic: small examples? Date: Sat, 28 Aug 2021 03:36:53 +0200 Message-ID: <87y28mbb9m.fsf@zoho.eu> References: <4a9bddb9ec57299b3b0c@heytings.org> <87y293sdxk.fsf@zoho.eu> <87pmufs4er.fsf@zoho.eu> <87wnompmpw.fsf@zoho.eu> <87k0kmgycz.fsf@gnus.org> <87y292nya4.fsf@zoho.eu> <87o89r5uwc.fsf@zoho.eu> <871r6hksj1.fsf@zoho.eu> Reply-To: Emanuel Berg Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="10956"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:6gIBCy/vkf0qARbUcRMb8Ak5bTs= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sat Aug 28 03:37:29 2021 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 1mJnHl-0002bX-7N for geh-help-gnu-emacs@m.gmane-mx.org; Sat, 28 Aug 2021 03:37:29 +0200 Original-Received: from localhost ([::1]:59990 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mJnHk-00054j-3T for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 27 Aug 2021 21:37:28 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:57344) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mJnHQ-00054a-N9 for help-gnu-emacs@gnu.org; Fri, 27 Aug 2021 21:37:08 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:39894) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mJnHO-0003eY-NP for help-gnu-emacs@gnu.org; Fri, 27 Aug 2021 21:37:08 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1mJnHK-0002BN-Sn for help-gnu-emacs@gnu.org; Sat, 28 Aug 2021 03:37:02 +0200 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 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 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:132787 Archived-At: Stefan Monnier via Users list for the GNU Emacs text editor wrote: > Of course. If the compiler says it's "not known to be > defined" that means the var isn't bound lexically (either > that, or there's a bug in the compiler), so it can only make > sense if the var is global or dynamically scoped (and both > are closely related). Check this out, here we seemingly define a global variable which isn't special/dynamic (because `special-variable-p' says it isn't) but it behaves like one anyway so I guess it is? Maybe it (the predicate) can only look at the definition and if it doesn't have an initial/default value it can't tell ... something? ;;; -*- lexical-binding: t -*- ;;; ;;; this file: ;;; https://dataswamp.org/~incal/emacs-init/scope.el ;;; ;;; g = global ;;; sd = special/dynamic ;;; ls = lexical/static ;;; v = variable (defvar gsd-v 1) ; 1 (special-variable-p 'gsd-v) ; t (defvar gls-v) (setq gls-v 2) ; 2 (special-variable-p 'gls-v) ; nil (defun fun-lol () (list gsd-v gls-v v) ) (setq lexical-binding nil) (let ((gsd-v 100) (gls-v 200) (v 300) ) (list (list gsd-v gls-v v) (fun-lol) )) ; ((100 200 300) (100 200 300)) (setq lexical-binding t) (let ((gsd-v 100) (gls-v 200) (v 300) ) (list (list gsd-v gls-v v) (fun-lol) )) ; DNC, lexical/static `let' binding v undefined in fun-lol (defun fun-lol-2 () (list gsd-v gls-v) ) (let ((gsd-v 100) (gls-v 200) (v 300) ) (list (list gsd-v gls-v v) (fun-lol-2) )) ; ((100 200 300) (100 200)) -- underground experts united https://dataswamp.org/~incal