From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.bugs Subject: bug#40671: [DOC] modify literal objects Date: Tue, 28 Apr 2020 10:59:40 -0700 Organization: UCLA Computer Science Department Message-ID: <293d0eab-4617-08fe-aafa-d6841a750af0@cs.ucla.edu> References: <9e6c138d-cb9f-6075-34df-a8d1d931343b@cs.ucla.edu> <871rofxbz9.fsf@web.de> <93463227-33a8-85a0-fd19-8b29b75997f3@yandex.ru> <969b3497-0afd-d104-6792-d744d31548fa@cs.ucla.edu> <2935ec84-bdea-2e20-01b9-8ed08cc61c6c@yandex.ru> <669981e5-f601-5c18-1a8b-ee316ad001ec@cs.ucla.edu> <4b8b7e98-029e-58ac-59ff-6cd984b7eb85@yandex.ru> <530d3597-aaaa-f019-bafa-8229d13e7248@yandex.ru> <60b88f52-c50d-c57a-9ce5-495e6157d36e@cs.ucla.edu> <0721d8c1-4fe3-335c-7dbc-171487cb648a@yandex.ru> <6d1015da-0dc1-376c-f84b-5e3ee3149213@cs.ucla.edu> <286139d2-bbe1-2d5a-bec1-f781666376f1@yandex.ru> <10b89e6f-6fa6-f855-65b6-3361a74472d3@cs.ucla.edu> <8542efe2-c4a6-1da5-2513-7ffcaa6c4ec9@yandex.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="99248"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 Cc: Michael Heerdegen , Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= , ke.vigouroux@laposte.net, 40671@debbugs.gnu.org, Richard Stallman To: Dmitry Gutov Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Tue Apr 28 20:02:58 2020 Return-path: Envelope-to: geb-bug-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 1jTUZO-000Pgw-3O for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 28 Apr 2020 20:02:58 +0200 Original-Received: from localhost ([::1]:43292 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jTUZM-0000UO-Vx for geb-bug-gnu-emacs@m.gmane-mx.org; 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Tue, 28 Apr 2020 10:59:41 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id mSERuixJN5j0; Tue, 28 Apr 2020 10:59:41 -0700 (PDT) Original-Received: from [192.168.1.9] (cpe-23-242-74-103.socal.res.rr.com [23.242.74.103]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 0864316008E; Tue, 28 Apr 2020 10:59:41 -0700 (PDT) Autocrypt: addr=eggert@cs.ucla.edu; prefer-encrypt=mutual; keydata= LS0tLS1CRUdJTiBQR1AgUFVCTElDIEtFWSBCTE9DSy0tLS0tCgptUUlOQkV5QWNtUUJFQURB QXlIMnhvVHU3cHBHNUQzYThGTVpFb243NGRDdmM0K3ExWEEySjJ0QnkycHdhVHFmCmhweHhk R0E5Smo1MFVKM1BENGJTVUVnTjh0TFowc2FuNDdsNVhUQUZMaTI0NTZjaVNsNW04c0thSGxH ZHQ5WG0KQUF0bVhxZVpWSVlYL1VGUzk2ZkR6ZjR4aEVtbS95N0xiWUVQUWRVZHh1NDd4QTVL aFRZcDVibHRGM1dZRHoxWQpnZDdneDA3QXV3cDdpdzdlTnZub0RUQWxLQWw4S1lEWnpiRE5D UUdFYnBZM2VmWkl2UGRlSStGV1FONFcra2doCnkrUDZhdTZQcklJaFlyYWV1YTdYRGRiMkxT MWVuM1NzbUUzUWpxZlJxSS9BMnVlOEpNd3N2WGUvV0szOEV6czYKeDc0aVRhcUkzQUZINmls QWhEcXBNbmQvbXNTRVNORnQ3NkRpTzFaS1FNcjlhbVZQa25qZlBtSklTcWRoZ0IxRApsRWR3 MzRzUk9mNlY4bVp3MHhmcVQ2UEtFNDZMY0ZlZnpzMGtiZzRHT1JmOHZqRzJTZjF0azVlVThN Qml5Ti9iClowM2JLTmpOWU1wT0REUVF3dVA4NGtZTGtYMndCeHhNQWhCeHdiRFZadWR6eERa SjFDMlZYdWpDT0pWeHEya2wKakJNOUVUWXVVR3FkNzVBVzJMWHJMdzYrTXVJc0hGQVlBZ1Jy NytLY3dEZ0JBZndoU In-Reply-To: <8542efe2-c4a6-1da5-2513-7ffcaa6c4ec9@yandex.ru> Content-Language: en-US X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-Received-From: 209.51.188.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:179237 Archived-At: On 4/28/20 6:54 AM, Dmitry Gutov wrote: > It shouldn't be changed because it's a value of a string literal. Not because > it's constant (it isn't). That depends on the string literal and the particular Emacs implementation. In Emacs master, some string literals yield strings that are constant because Emacs has undefined behavior at the C level (maybe coredump, maybe not) if you try to change them, some string literals are constant because if you try to change them Emacs will reliably signal an error, some string literals are constant because if you change them Emacs might behave unpredictably without having undefined behavior at the C level, and the remaining string literals are constant becase you shouldn't change them. We have never documented exactly which string literals are which, and we shouldn't document that now because it is an implementation detail that users should not rely upon. It would be a mistake for the documentation to say that the problems we've been discussing occur only with string literals, as these problems can occur for strings that were not generated from string literals, and they can also occur for objects that are not strings. So "string literal" would be the wrong terminology here.