From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Mark H Weaver Newsgroups: gmane.lisp.guile.devel Subject: Re: (set! (@@ MOD NAME) EXP) considered harmful Date: Wed, 2 Sep 2009 12:25:05 -0400 Message-ID: <20090902162505.GA3339@fibril.netris.org> References: <877hwhqq2g.fsf@netris.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1251908926 31494 80.91.229.12 (2 Sep 2009 16:28:46 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 2 Sep 2009 16:28:46 +0000 (UTC) To: guile-devel@gnu.org Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Wed Sep 02 18:28:39 2009 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1Mish7-0000VJ-JC for guile-devel@m.gmane.org; Wed, 02 Sep 2009 18:28:25 +0200 Original-Received: from localhost ([127.0.0.1]:58011 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Mish6-0000MX-V4 for guile-devel@m.gmane.org; Wed, 02 Sep 2009 12:28:24 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Mise5-0005FX-VB for guile-devel@gnu.org; Wed, 02 Sep 2009 12:25:18 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Mise1-00059S-16 for guile-devel@gnu.org; Wed, 02 Sep 2009 12:25:17 -0400 Original-Received: from [199.232.76.173] (port=38499 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Mise0-00058t-Lh for guile-devel@gnu.org; Wed, 02 Sep 2009 12:25:12 -0400 Original-Received: from world.peace.net ([204.107.200.8]:44329) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1Misdz-0001el-DH for guile-devel@gnu.org; Wed, 02 Sep 2009 12:25:11 -0400 Original-Received: from localhost ([127.0.0.1] helo=fibril.netris.org ident=hope3) by world.peace.net with esmtp (Exim 4.69) (envelope-from ) id 1Misdt-0002m7-SL; Wed, 02 Sep 2009 12:25:06 -0400 Content-Disposition: inline In-Reply-To: <877hwhqq2g.fsf@netris.org> X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 3) X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Developers list for Guile, the GNU extensibility library" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Errors-To: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.devel:9253 Archived-At: Sorry, I meant to say that (set! (@ MOD NAME) EXP) should be considered harmful as well. Mark On Wed, Sep 02, 2009 at 12:17:11PM -0400, Mark H Weaver wrote: > The ability to set! arbitrary module top-level variables from outside > the module, using the syntax (set! (@@ MOD NAME) EXP), destroys our > ability to several important optimizations. > > As long as such ability exists, we must pessimistically assume that > any module top-level variable might change at any time, which means, > for example, that we cannot inline top-level procedure applications > from within the module itself. This could be a HUGE efficiency win in > the common case where such top-level procedures are never set! from > within the module. > > Now that we have proper hygienic macros, is this functionality still > required? If we're going to remove it, pre-2.0 seems like a good time > to do so. We won't get another opportunity for several years. > > Mark >