From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Ihor Radchenko Newsgroups: gmane.emacs.devel Subject: Re: Emacs design and architecture. How about copy-on-write? Date: Wed, 20 Sep 2023 09:59:45 +0000 Message-ID: <87o7hx88ry.fsf@localhost> References: <83edizjn0v.fsf@gnu.org> <0518f65b-1dd1-6923-8497-da4d3aeac631@gutov.dev> <87sf7fc7kd.fsf@dataswamp.org> <834jjuk68t.fsf@gnu.org> <87cyyhc7uu.fsf@dataswamp.org> <83ttrsg9nx.fsf@gnu.org> <83h6nrg4eg.fsf@gnu.org> <83v8c7elan.fsf@gnu.org> <877conk5ny.fsf@localhost> <83ttrreeu0.fsf@gnu.org> <87bkdzeas1.fsf@localhost> <83cyyfe5l8.fsf@gnu.org> <8734zbyu6o.fsf@dataswamp.org> <835y46e8o9.fsf@gnu.org> <87zg1ixvnc.fsf@dataswamp.org> <87il86nxts.fsf@localhost> <87o7hyx8h2.fsf@dataswamp.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="7030"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Emanuel Berg Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Wed Sep 20 11:58:58 2023 Return-path: Envelope-to: ged-emacs-devel@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 1qityz-0001dK-L9 for ged-emacs-devel@m.gmane-mx.org; Wed, 20 Sep 2023 11:58:57 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qityn-0005Rf-In; Wed, 20 Sep 2023 05:58:46 -0400 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 1qityd-0005G2-Cr for emacs-devel@gnu.org; Wed, 20 Sep 2023 05:58:38 -0400 Original-Received: from mout02.posteo.de ([185.67.36.66]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qityb-0002Uk-Gb for emacs-devel@gnu.org; Wed, 20 Sep 2023 05:58:35 -0400 Original-Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 3790E240104 for ; Wed, 20 Sep 2023 11:58:31 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1695203911; bh=MrTDjh1zpIxWXvFKPmJ3An1G4jbeDRfzbG/x5l1kq7s=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:From; b=EwKi2UCf0qdxz0k7/7Qq+0JnXU5XzhfyLjE/AW66iZilpYIzP62PHIlbJxGzPNFI6 FVP6yiDoQo4Ta7ggZzSk+qnRQw3OUgRL3vS7PQapPQQnzHKLBq9k33hwWf72NnnnlN n6lM/N3O7c7npwNM3cr88X1UQ5N5eIBSYu+LeeuzZJKPDJXGaG4felGlKT0dJg40Mx 8Ml8VIANJZcjRYjP1t1MNtAIGGGEUEbIajWR4sFLWHSa4K0Ob9JwpCRt0PppxAhIM1 iYhvVd0wkQwyymsmsfX74trv6x6b3L0teNXI3pYvY8mVnrMJIexFArtmTkj/mXYpx+ 2vvsd9K/pJt+w== Original-Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4RrDWB3Q8nz6tyY; Wed, 20 Sep 2023 11:58:30 +0200 (CEST) In-Reply-To: <87o7hyx8h2.fsf@dataswamp.org> Received-SPF: pass client-ip=185.67.36.66; envelope-from=yantar92@posteo.net; helo=mout02.posteo.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:310812 Archived-At: Emanuel Berg writes: > Ihor Radchenko wrote: > >> Because implementation details are tricky - a lot of Elisp >> internal machinery is relying upon modifying global symbol >> objects [...] > > Yeah, but that should be fine, as long as they are locked and > unlocked safely, right? No. If we have something like (let ((case-fold-search t)) ...), we will lock `case-fold-search' symbol for the whole duration of `let' call and block any other threads trying to alter `case-fold-search' locally. > But, if one aspire to reduce the number of global variables > used, a great way of doing that is lexical `let'-closures, > here is an example that allows for the same default value when > the function is called from Lisp and when used as an > interactive command, yet the data is only hardcoded once for > each variable. Not every variable can be used within lexical scope. In particular special variables (see 12.10.4 Using Lexical Binding and `special-variable-p') are always treated outside lexical binding. -- Ihor Radchenko // yantar92, Org mode contributor, Learn more about Org mode at . Support Org development at , or support my work at