From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Kevin Ryde Newsgroups: gmane.lisp.guile.devel Subject: Re: while break and continue Date: Fri, 15 Aug 2003 11:43:01 +1000 Sender: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Message-ID: <87fzk366hm.fsf@zip.com.au> References: <87isrtmhfw.fsf@zip.com.au> <87he79ic44.fsf@zagadka.ping.de> <878yshe1ux.fsf@zip.com.au> <87n0gf0zbc.fsf@zagadka.ping.de> <87fzm3m2n9.fsf@zip.com.au> <87smosrpp0.fsf@zagadka.ping.de> <8765lmkwpb.fsf@zip.com.au> <87znid1b4l.fsf@zip.com.au> NNTP-Posting-Host: deer.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1060912115 19393 80.91.224.253 (15 Aug 2003 01:48:35 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Fri, 15 Aug 2003 01:48:35 +0000 (UTC) Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Fri Aug 15 03:48:33 2003 Return-path: Original-Received: from monty-python.gnu.org ([199.232.76.173]) by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 19nThh-0003gL-00 for ; Fri, 15 Aug 2003 03:48:33 +0200 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.20) id 19nTgk-0007T6-Sm for guile-devel@m.gmane.org; Thu, 14 Aug 2003 21:47:34 -0400 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.20) id 19nTfg-0006xn-4j for guile-devel@gnu.org; Thu, 14 Aug 2003 21:46:28 -0400 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.20) id 19nTe0-0006EB-0v for guile-devel@gnu.org; Thu, 14 Aug 2003 21:45:15 -0400 Original-Received: from [61.8.0.36] (helo=snoopy.pacific.net.au) by monty-python.gnu.org with esmtp (Exim 4.20) id 19nTcZ-0004Ip-Lq for guile-devel@gnu.org; Thu, 14 Aug 2003 21:43:15 -0400 Original-Received: from sunny.pacific.net.au (sunny.pacific.net.au [203.2.228.40]) by snoopy.pacific.net.au (8.12.3/8.12.3/Debian-6.4) with ESMTP id h7F1hE0J021906 for ; Fri, 15 Aug 2003 11:43:14 +1000 Original-Received: from wisma.pacific.net.au (wisma.pacific.net.au [210.23.129.72]) by sunny.pacific.net.au with ESMTP id h7F1hDkv000881 for ; Fri, 15 Aug 2003 11:43:13 +1000 (EST) Original-Received: from localhost (ppp19.dyn228.pacific.net.au [203.143.228.19]) by wisma.pacific.net.au (8.12.9/8.12.9) with ESMTP id h7F1hBos008554 for ; Fri, 15 Aug 2003 11:43:12 +1000 (EST) Original-Received: from gg by localhost with local (Exim 3.35 #1 (Debian)) id 19nTcP-000124-00; Fri, 15 Aug 2003 11:43:05 +1000 Original-To: guile-devel@gnu.org Mail-Copies-To: never In-Reply-To: (Matthias Koeppe's message of "Wed, 13 Aug 2003 11:27:13 +0200") User-Agent: Gnus/5.090019 (Oort Gnus v0.19) Emacs/21.2 (gnu/linux) X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.2 Precedence: list List-Id: Developers list for Guile, the GNU extensibility library List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Xref: main.gmane.org gmane.lisp.guile.devel:2696 X-Report-Spam: http://spam.gmane.org/gmane.lisp.guile.devel:2696 Matthias Koeppe writes: > > I think you need a fresh catch tag for every invocation (not only for > every macro expansion site) of WHILE. I think this might do the trick. A separate helper is an easy way to keep the "key" binding from being exposed to the cond and body. (define-macro (while cond . body) (define (while-helper proc) (do ((key (make-symbol "while-key"))) ((catch key (lambda () (proc (lambda () (throw key #t)) (lambda () (throw key #f)))) (lambda (key arg) arg))))) `(,while-helper (,lambda (break continue) (,do () ((,not ,cond)) ,@body) #t))) _______________________________________________ Guile-devel mailing list Guile-devel@gnu.org http://mail.gnu.org/mailman/listinfo/guile-devel