From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: ludo@gnu.org (Ludovic =?iso-8859-1?Q?Court=E8s?=) Newsgroups: gmane.lisp.guile.devel Subject: Re: srfe records in reworked match Date: Fri, 23 Apr 2010 11:23:33 +0200 Message-ID: <87ochattd6.fsf@gnu.org> References: <201004201514.18375.stefan.tampe@spray.se> <878w8hkxky.fsf@gnu.org> <201004230952.42913.stefan.tampe@spray.se> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: dough.gmane.org 1272014766 21054 80.91.229.12 (23 Apr 2010 09:26:06 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 23 Apr 2010 09:26:06 +0000 (UTC) To: guile-devel@gnu.org Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Fri Apr 23 11:26:01 2010 connect(): No such file or directory 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 4.69) (envelope-from ) id 1O5F95-0005d5-HO for guile-devel@m.gmane.org; Fri, 23 Apr 2010 11:25:59 +0200 Original-Received: from localhost ([127.0.0.1]:35859 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O5F94-0007Y2-CG for guile-devel@m.gmane.org; Fri, 23 Apr 2010 05:25:58 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O5F70-0006e6-Dd for guile-devel@gnu.org; Fri, 23 Apr 2010 05:23:50 -0400 Original-Received: from [140.186.70.92] (port=46391 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O5F6y-0006d7-6d for guile-devel@gnu.org; Fri, 23 Apr 2010 05:23:49 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1O5F6w-0000pt-C1 for guile-devel@gnu.org; Fri, 23 Apr 2010 05:23:47 -0400 Original-Received: from lo.gmane.org ([80.91.229.12]:59147) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1O5F6w-0000pb-52 for guile-devel@gnu.org; Fri, 23 Apr 2010 05:23:46 -0400 Original-Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1O5F6t-00045Y-8l for guile-devel@gnu.org; Fri, 23 Apr 2010 11:23:43 +0200 Original-Received: from acces.bordeaux.inria.fr ([193.50.110.5]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 23 Apr 2010 11:23:43 +0200 Original-Received: from ludo by acces.bordeaux.inria.fr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 23 Apr 2010 11:23:43 +0200 X-Injected-Via-Gmane: http://gmane.org/ connect(): No such file or directory Original-Lines: 30 Original-X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: acces.bordeaux.inria.fr X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 4 =?iso-8859-1?Q?Flor=E9al?= an 218 de la =?iso-8859-1?Q?R=E9volution?= X-PGP-Key-ID: 0xEA52ECF4 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 83C4 F8E5 10A3 3B4C 5BEA D15D 77DD 95E2 EA52 ECF4 X-OS: x86_64-unknown-linux-gnu User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) Cancel-Lock: sha1:mLN6cLO0RK+7janqyi762QUC5J4= X-detected-operating-system: by eggs.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:10295 Archived-At: Hi, stefan writes: > On Wednesday 21 April 2010 10:40:29 am Ludovic Courtès wrote: >> As noted in Shinn’s match-cond-expand.scm, this record matching form is >> not ideal: >> >> ;; Annoying unhygienic record matching. Record patterns look like >> ;; ($ record fields...) >> ;; where the record name simply assumes that the same name suffixed >> ;; with a "?" is the correct predicate. >> > > Entering, > > scheme@(guile-user)> (macroexpand '(n? x)) > (if (struct? x) (eq? (struct-vtable x) n) #f) That’s an implementation detail that you should ignore. :-) Just have users write: (($ n? a b c) ...) Where ‘n?’ is bound to the record type predicate, and have ‘match’ invoke that record type predicate. Thanks, Ludo’.