From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Helmut Eller Newsgroups: gmane.emacs.devel Subject: Re: rx.el sexp regexp syntax Date: Sun, 03 Jun 2018 17:53:00 +0200 Message-ID: References: <87h8mw3yoc.fsf@gmail.com> <20180525155126.GA4096@ACM> <87lgc7hebk.fsf@gmail.com> <87r2lzd375.fsf@ericabrahamsen.net> <87lgbx2dc1.fsf@ericabrahamsen.net> <87in6z6gwa.fsf@ericabrahamsen.net> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1528041072 20575 195.159.176.226 (3 Jun 2018 15:51:12 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sun, 3 Jun 2018 15:51:12 +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 Sun Jun 03 17:51:08 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 1fPVHg-0005GJ-Cp for ged-emacs-devel@m.gmane.org; Sun, 03 Jun 2018 17:51:08 +0200 Original-Received: from localhost ([::1]:35694 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fPVJn-0003re-Ll for ged-emacs-devel@m.gmane.org; Sun, 03 Jun 2018 11:53:19 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:35916) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fPVJh-0003rL-R3 for emacs-devel@gnu.org; Sun, 03 Jun 2018 11:53:14 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fPVJe-0005NI-JE for emacs-devel@gnu.org; Sun, 03 Jun 2018 11:53:13 -0400 Original-Received: from [195.159.176.226] (port=34105 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fPVJe-0005Mf-Ac for emacs-devel@gnu.org; Sun, 03 Jun 2018 11:53:10 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1fPVHU-00051i-Uh for emacs-devel@gnu.org; Sun, 03 Jun 2018 17:50:56 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 21 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:kPX9rf2ITcfDpz/a6fxka/yF5EU= 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:225961 Archived-At: On Sun, Jun 03 2018, Eric Abrahamsen wrote: >> Maybe we could start with an ordinary macro, e.g. (pcre "(a|b)"), which >> could translate Perl/Python regexp syntax to Emacs regexp syntax. > > I made something like that, but the only advantage is your example > above: open and close parentheses, and the vertical bar. Everything else > still has to be double-backslashed. It feels inconsistent, and isn't > that much of a benefit... Any benefit on a small example is bound to be small. And yes, in practice most regexps fit on a single line. i.e. they are small. I'm not sure what you mean with "everything else" as in this example there's nothing else. The example would translate to: "\\(a\\|\\b\\)" which, while it is one character shorter, is also quite ugly. Maybe you mean that things like \w cannot occur in ordinary strings without double-backslash. Hmm.. that's indeed a problem. Helmut