From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Stephen J. Turnbull" Newsgroups: gmane.emacs.devel Subject: Re: Emacs rewrite in a maintainable language Date: Sun, 18 Oct 2015 03:31:52 +0900 Message-ID: <22050.37912.478909.965633@turnbull.sk.tsukuba.ac.jp> References: <561A19AB.5060001@cumego.com> <87io6dl0h0.fsf@wanadoo.es> <87lhb82qxc.fsf@gmail.com> <87oag4jk74.fsf@wanadoo.es> <87k2qrki45.fsf@wanadoo.es> <8737xf9je9.fsf@fencepost.gnu.org> <87pp0fm0j3.fsf@gnu.org> <87r3kusx8z.fsf@fencepost.gnu.org> <83lhb26eb9.fsf@gnu.org> <876126key3.fsf@gnu.org> <83fv1a6bfu.fsf@gnu.org> <87d1weo7u9.fsf@gnu.org> <83zizi3qr0.fsf@gnu.org> <87lhb1n81y.fsf@gnu.org> <87a8rhqzdd.fsf@fencepost.gnu.org> <871tctxy1a.fsf@T420.taylan> <83fv194f0v.fsf@gnu.org> <87k2qlwhpl.fsf@T420.taylan> <83d1wd4e19.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1445106740 29410 80.91.229.3 (17 Oct 2015 18:32:20 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 17 Oct 2015 18:32:20 +0000 (UTC) Cc: emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Oct 17 20:32:08 2015 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ZnWH1-0005wY-GV for ged-emacs-devel@m.gmane.org; Sat, 17 Oct 2015 20:32:07 +0200 Original-Received: from localhost ([::1]:59435 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZnWH0-00085M-QX for ged-emacs-devel@m.gmane.org; Sat, 17 Oct 2015 14:32:06 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:34780) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZnWGx-00084v-0G for emacs-devel@gnu.org; Sat, 17 Oct 2015 14:32:04 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZnWGw-0002LR-5Q for emacs-devel@gnu.org; Sat, 17 Oct 2015 14:32:02 -0400 Original-Received: from turnbull.sk.tsukuba.ac.jp ([130.158.96.25]:37980) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZnWGs-0002JE-67; Sat, 17 Oct 2015 14:31:58 -0400 Original-Received: from steve by turnbull.sk.tsukuba.ac.jp with local (Exim 4.86) (envelope-from ) id 1ZnWGm-0000QW-JQ; Sun, 18 Oct 2015 03:31:52 +0900 In-Reply-To: <83d1wd4e19.fsf@gnu.org> X-Mailer: VM 8.0.12-devo-585 under 21.5 (beta34) "kale" 698a9aa86de4 XEmacs Lucid (x86_64-apple-darwin14.5.0) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: steve@turnbull.sk.tsukuba.ac.jp X-SA-Exim-Scanned: No (on turnbull.sk.tsukuba.ac.jp); SAEximRunCond expanded to false X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 130.158.96.25 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:191870 Archived-At: Eli Zaretskii writes: > > Rewriting select parts of it in Elisp and/or Scheme seems much more > > realistic. > > But then it's prudent to ask do the gains justify the effort. Rewriting "select" parts in Elisp clearly do, at least they have up to now. People regularly rewrite C features in Elisp when they run into the inflexiblity of C (I suppose my estimate is biased since it's based on [S]XEmacs practice, not Emacs, but [S]XEmacs practice is somewhat relevant here, and I imagine Emacs practice is not so different). Rewriting "select" parts in Scheme makes very little sense IMO (unless you're already running GuileEmacs). The cost of moving large parts of core to Scheme not only includes the rewrites themselves (which I suspect mostly have *not* yet been done in GuileEmacs), but the not- to-be-underestimated costs of integrating a large branch, as well. And of course it has a strong (partial) effect of *increasing* maintenance cost, because the maintainers now have to be familiar with 3 different languages.