From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Po Lu Newsgroups: gmane.emacs.devel Subject: Re: Unbinding let-bound built-in variables Date: Thu, 23 May 2024 15:31:11 +0800 Message-ID: <87le41c7cw.fsf@yahoo.com> References: <87pltdcaa7.fsf.ref@yahoo.com> <87pltdcaa7.fsf@yahoo.com> <86a5kh57do.fsf@gnu.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="21515"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu May 23 09:32:46 2024 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 1sA2wO-0005PA-Vz for ged-emacs-devel@m.gmane-mx.org; Thu, 23 May 2024 09:32:45 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sA2vR-00035v-Cx; Thu, 23 May 2024 03:31:45 -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 1sA2vC-00032h-Ta for emacs-devel@gnu.org; Thu, 23 May 2024 03:31:33 -0400 Original-Received: from sonic310-23.consmr.mail.ne1.yahoo.com ([66.163.186.204]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sA2v6-0001JW-U5 for emacs-devel@gnu.org; Thu, 23 May 2024 03:31:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1716449482; bh=h9RB/yVHKIESVsdRiknznb6s6nM0fQODIWPLaw280SQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From:Subject:Reply-To; b=Yl+BYuNOwh/Jtg1kwweM9HWePlTHRlFPXEqibS9int7JgeQAv86sKM0ZaQnU5wUoSVVYgcT/7iBVczfHygpKnDaFGiGIsMVT/JSAwZ0EuYSXnT78UZBrftpxIV6blWmcGyIhq+st3RLL0MVvF6oXD/BfWwY2hCHITfoilh6xpoDPVw00L2uW143sGzUPlWN9SxQpDv+hR1YYntFzkLMj6+XYJcejnIIKoXBwx90RqICliMExbaGFK+EZA61zy65pwvqYqQvLK3z5w2BNSceu3hvojlOe6Cy5qjSljKRFQ91mOLLDJJ5UtifDWLYy3PAFOv+TPrdArWws6HosRFI75g== X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1716449482; bh=EE5dM5PCjPFLdNlLmeuZUi2xvszt0Yz1TLevb0oOoQc=; h=X-Sonic-MF:From:To:Subject:Date:From:Subject; b=Xc99aUVlX/fkiAVljvuFtBj9UAzu+W/FE7KjTlfUzx+xuabVZTyHz4BSvQuyKKhF3Q9M/jRbiwlosUjvedzgjWKBZC5BR+x/dcSJtPK1k7P5wxJvyn5gjHVECed1Xdq6278mRkLlECKi+VS0Msn2mfUH644JMoFADGJyWJBKfJlJhcdgJodbmfbzbtTKzv/WY5AiMet4r35ye32uN1KtsyvIjlc96NQrUzBAjeQKX6G3oLXy2iAhNi8G2a3G+sTymFTPTNOnqKwc63CqEtRjKl9neVsk59ErJ/Y6lfRUcgv081OAe1gTW75wnOUicElhJROgcCNETpWui83w/8nHKg== X-YMail-OSG: Jj5EpfYVM1ln1zmRYdZk3tWSB3WB_jQUsUBx.Q14dEwcOmemdy6qJdbthMxQpJw jLKPHIsx5uecw1lkIx6EDd1.7nX.vNEqFrQMaHUlC6A2L.AaXkOrbB11sWRr6p1_WWLQb80h8c54 CEbOESwvDJSR.tue1DXWkwIH0onwA2JrgQbms7vKsowLhLYbkXYX9aKyX4Im7SK6gljWx2nuIKKC lh7C_SjDcYwoN6akveaHHWIiFEslZe3TS_NK.33lAZmrIGXA9eqWxsE.xfM32qaNhPkQ4RcPGtgr 8ou0lEPhX7UDyKIyJ_vR3E60sV5733UlpVHu2RMzpbFeeQATRzPj0mOnHCnv9q_82bKrTXhhV6yc .N_iAcHSZ6PJcXT3ZHEU_MPesOVShEXRHx7g0rFoR7VVwrwpBqUJeq2m5HKC3NonBQUfpd5Rh2Zj u9NmWQXS8LHN.SBR22TsHGZD3eBaGkb3CDjc7uZgU_jGCNtOfaXo6npTBnPMGZHWE6drsBewiEwj IZUivVpYg1kNfFYDxrJ153JCHsnXcI0jhdhOwVM9fYLbrP8_g3ANQD25YanKH8feIwKP8MQ6We2c Rg9.wLo_hjn4bUs8RK40yoBmCJIr.tKqUUG85mhemcQOzttVZiPlbcDJG6Glo4P8zvzvfFf6x.5D aneG1Y8vHg3X6ax6JED6SuFG9SyaBhUKaQfphkZikf60wqsk7yoQU52YHcgrbVdp.xNPZoxDnC4p eplchgnerGRy3nEM5aoGbj0QEMZH4Yl9LT0MgjOs92HuMvKVCU1s1vfZK5XcW_qDPwkGPzv0g1zv rmg0SaWdpkMxBI6PNTia9KHfOCexXGp9cjFhkiCE3Z X-Sonic-MF: X-Sonic-ID: 42c01023-91c2-42e5-8d63-f247775c7b89 Original-Received: from sonic.gate.mail.ne1.yahoo.com by sonic310.consmr.mail.ne1.yahoo.com with HTTP; Thu, 23 May 2024 07:31:22 +0000 Original-Received: by hermes--production-sg3-6f9f87bd85-t6lxr (Yahoo Inc. Hermes SMTP Server) with ESMTPA ID 3614792f3a3c1d8fa932b28f6bb5a5a9; Thu, 23 May 2024 07:31:16 +0000 (UTC) In-Reply-To: <86a5kh57do.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 23 May 2024 10:12:35 +0300") X-Mailer: WebService/1.1.22356 mail.backend.jedi.jws.acl:role.jedi.acl.token.atz.jws.hermes.yahoo Received-SPF: pass client-ip=66.163.186.204; envelope-from=luangruo@yahoo.com; helo=sonic310-23.consmr.mail.ne1.yahoo.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-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:319502 Archived-At: Eli Zaretskii writes: > Why should it be resolved? What practical problems do you need to > solve that require the technique such as above? The problem that it is impossible to protect a built-in variable against being made unbound, and more importantly, that variables so unbound become useless without any external indication of the fact, being ostensibly bound after the let completes and the makunbound is "reverted". Knowing of this bug in advance would have spared me an hour of bewilderment.