From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eric Abrahamsen Newsgroups: gmane.emacs.devel Subject: Re: rx.el sexp regexp syntax Date: Sat, 02 Jun 2018 12:33:18 -0700 Message-ID: <87lgbx2dc1.fsf@ericabrahamsen.net> References: <87h8mw3yoc.fsf@gmail.com> <20180525155126.GA4096@ACM> <87lgc7hebk.fsf@gmail.com> <87r2lzd375.fsf@ericabrahamsen.net> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1527968097 30616 195.159.176.226 (2 Jun 2018 19:34:57 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 2 Jun 2018 19:34:57 +0000 (UTC) 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 Jun 02 21:34:53 2018 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fPCIe-0007rD-Gq for ged-emacs-devel@m.gmane.org; Sat, 02 Jun 2018 21:34:52 +0200 Original-Received: from localhost ([::1]:60859 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fPCKl-0000E2-MZ for ged-emacs-devel@m.gmane.org; Sat, 02 Jun 2018 15:37:03 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:59133) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fPCK6-0000Dw-LS for emacs-devel@gnu.org; Sat, 02 Jun 2018 15:36:23 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fPCK3-0003lM-JC for emacs-devel@gnu.org; Sat, 02 Jun 2018 15:36:22 -0400 Original-Received: from [195.159.176.226] (port=45582 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fPCK3-0003jn-C2 for emacs-devel@gnu.org; Sat, 02 Jun 2018 15:36:19 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1fPCHu-00075w-6t for emacs-devel@gnu.org; Sat, 02 Jun 2018 21:34:06 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 20 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:J/5n6uRGFB5eftZtHB331+/Jpoc= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] 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:225936 Archived-At: Stefan Monnier writes: >> brutal regexp, but what I *would* use all day long would be a macro that >> un-escaped backslashes for me. Ideally: > > That'd be a good first step. > A second important step would be to easily embed comments and Elisp code > (mostly references to other Elisp variables). I played around with this, but it might not be possible to achieve enough of the conveniences to make it worthwhile. I wanted to partially reverse the sense of the backslash -- "(" would be translated to "\\(" -- but also to write backslash specials with a single backslash: ie the first group reference could actually be written as "\1", rather than "\\1". Of course, the string reader interprets that as a control character, and I doubt there's any way around that, at least not in lisp. It's still nice to be able to write "\\(cat\\|dog\\)" as "(cat|dog)", but I'm not sure it's worth it.