From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: "Perry E. Metzger" Newsgroups: gmane.emacs.devel Subject: Re: [Emacs-diffs] master 938d252 4/4: Make regex matching reentrant; update syntax during match Date: Tue, 19 Jun 2018 11:32:43 -0400 Message-ID: <20180619113243.69f0bdcc@jabberwock.cb.piermont.com> References: <20180616204650.8423.73499@vcs0.savannah.gnu.org> <20180616204653.86AFC203CB@vcs0.savannah.gnu.org> <04e89d2beffedcc102b811863910c1ec.squirrel@dancol.org> <20180618115941.4f22a9d3@jabberwock.cb.piermont.com> <1de38eca2662563e9e08006c88a6d2e5.squirrel@dancol.org> <20180619094005.11465a87@jabberwock.cb.piermont.com> <20180619094442.41287e4b@jabberwock.cb.piermont.com> <20180619103002.4f000018@jabberwock.cb.piermont.com> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1529422252 27980 195.159.176.226 (19 Jun 2018 15:30:52 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 19 Jun 2018 15:30:52 +0000 (UTC) Cc: Daniel Colascione , Stefan Monnier , emacs-devel@gnu.org To: Andreas Schwab Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Jun 19 17:30:47 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 1fVIal-0007Ck-6j for ged-emacs-devel@m.gmane.org; Tue, 19 Jun 2018 17:30:47 +0200 Original-Received: from localhost ([::1]:43280 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fVIcs-0000fj-Bf for ged-emacs-devel@m.gmane.org; Tue, 19 Jun 2018 11:32:58 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:60073) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fVIcg-0000dV-GY for emacs-devel@gnu.org; Tue, 19 Jun 2018 11:32:47 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fVIcf-0002Ii-Mc for emacs-devel@gnu.org; Tue, 19 Jun 2018 11:32:46 -0400 Original-Received: from hacklheber.piermont.com ([2001:470:30:84:e276:63ff:fe62:3400]:55078) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fVIcf-0002II-Hh for emacs-devel@gnu.org; Tue, 19 Jun 2018 11:32:45 -0400 Original-Received: from snark.cb.piermont.com (localhost [127.0.0.1]) by hacklheber.piermont.com (Postfix) with ESMTP id 4F0251AE; Tue, 19 Jun 2018 11:32:44 -0400 (EDT) Original-Received: from jabberwock.cb.piermont.com (jabberwock.cb.piermont.com [10.160.2.107]) by snark.cb.piermont.com (Postfix) with ESMTP id 121C02DEC77; Tue, 19 Jun 2018 11:32:44 -0400 (EDT) In-Reply-To: X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2001:470:30:84:e276:63ff:fe62:3400 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:226512 Archived-At: On Tue, 19 Jun 2018 16:58:15 +0200 Andreas Schwab wrote: > On Jun 19 2018, Daniel Colascione wrote: > > > IMHO, back reference support is an old unix mistake. I can't > > think of a time when I've wanted to actually use them, but their > > theoretical use is still a hindrance. One option would be to just > > deprecate them. > > There are quite a few uses in Emacs. I agree that they're a mistake, but we're a bit stuck. The right thing, I think, is using a library like TRE that uses a fast algorithm whenever a backreference isn't in use. Perry -- Perry E. Metzger perry@piermont.com