From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: cc-mode: Make all parameters introduced in Emacs 26 optional Date: Sat, 30 Mar 2019 12:39:55 -0400 Message-ID: References: <1516608561.1943450.1243462056.1A47A60F@webmail.messagingengine.com> <20180122203254.GA4888@ACM> <87k1vuwr3p.fsf@ahungry.com> <87fu6iwqfu.fsf@ahungry.com> <20180203114451.GA4806@ACM> <20190330135148.GA6312@ACM> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="14125"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Mar 30 17:41:07 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hAH2Z-0003Zk-FY for ged-emacs-devel@m.gmane.org; Sat, 30 Mar 2019 17:41:07 +0100 Original-Received: from localhost ([127.0.0.1]:58660 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hAH2Y-0000EL-HJ for ged-emacs-devel@m.gmane.org; Sat, 30 Mar 2019 12:41:06 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:60813) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hAH1z-0000CC-PZ for emacs-devel@gnu.org; Sat, 30 Mar 2019 12:40:32 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hAH1y-0006ws-Jc for emacs-devel@gnu.org; Sat, 30 Mar 2019 12:40:31 -0400 Original-Received: from [195.159.176.226] (port=42862 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hAH1l-0006m1-3Q for emacs-devel@gnu.org; Sat, 30 Mar 2019 12:40:19 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.89) (envelope-from ) id 1hAH1W-0002UJ-E3 for emacs-devel@gnu.org; Sat, 30 Mar 2019 17:40:02 +0100 X-Injected-Via-Gmane: http://gmane.org/ Cancel-Lock: sha1:u7mIogg7RUBy8KVf99o0xHz3XYA= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 195.159.176.226 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:234821 Archived-At: Hi Alan, > To set up a CC Mode derived mode to recognise strings 'like this', do the > following: > (i) Set the derived mode's value of `c-single-quotes-quote-strings' to t. > (This is done with `c-lang-defconst' in the derived mode's .el file). > (ii) Make sure the derived mode's value of > `c-get-state-before-change-function' does not include > `c-parse-quotes-before-change'. > (iii) Similarly ensure `c-before-font-lock-functions' doesn't contain > `c-parse-quotes-after-change'. > (iv) Ensure the derived mode's value of > `c-get-state-before-change-function' contains > `c-before-change-check-unbalanced-strings' and that of > `c-before-font-lock-functions' contains > 'c-after-change-mark-abnormal-strings'. > (v) Make sure `c-has-quoted-numbers' is nil. (This is a pure C++ > facility for writing numbers as 4'294'967'295.) > (vi) Ensure `c-multiline-string-start-char' (which allows strings to > continue over line ends without \) is set correctly for the mode. In non-CC modes, all it takes is (modify-syntax-entry ?' "\"" st) so is there somewhere in CC-mode's code where there's some comment or something that explains why this simple approach isn't sufficient? I understand that things aren't always that simple: - you need to handle the 4'294'967'295 thingies in C++, but that should only affect C++ and I'd assume that the C++ code handles it by recognizing something like "[0-9]'" and changing the syntax-class of those quotes so it shouldn't prevent multichar single-quoted strings. - you apparently want to help the user catch the erroneous use of single-quoted strings in those languages where single quotes are used for chars rather than strings. but again this would seem to only explain the need for c-single-quotes-quote-strings. But the above sounds surprisingly complex&scary, Stefan