From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Rob Browning Newsgroups: gmane.lisp.guile.devel Subject: Re: What are the arguments in favor of delay/force in eval.c? Date: Fri, 09 Dec 2005 20:23:53 -0800 Message-ID: <87oe3pwpeu.fsf@trouble.defaultvalue.org> References: <87hd9mgc7v.fsf@trouble.defaultvalue.org> <87acfcfvbr.fsf@zip.com.au> <87y82wo78b.fsf@trouble.defaultvalue.org> <8764q0fn2f.fsf@zip.com.au> <874q5kmmup.fsf@trouble.defaultvalue.org> <873bl13j6i.fsf@zip.com.au> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1134188671 4322 80.91.229.2 (10 Dec 2005 04:24:31 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Sat, 10 Dec 2005 04:24:31 +0000 (UTC) Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Sat Dec 10 05:24:30 2005 Return-path: Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1EkwHB-0006zL-It for guile-devel@m.gmane.org; Sat, 10 Dec 2005 05:24:01 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1EkwHY-0008Ek-JV for guile-devel@m.gmane.org; Fri, 09 Dec 2005 23:24:24 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1EkwHU-0008Ef-Ez for guile-devel@gnu.org; Fri, 09 Dec 2005 23:24:20 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1EkwHS-0008EP-Sk for guile-devel@gnu.org; Fri, 09 Dec 2005 23:24:20 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1EkwHS-0008EM-P2 for guile-devel@gnu.org; Fri, 09 Dec 2005 23:24:18 -0500 Original-Received: from [70.85.129.156] (helo=defaultvalue.org) by monty-python.gnu.org with esmtp (Exim 4.34) id 1EkwIl-0001of-V2 for guile-devel@gnu.org; Fri, 09 Dec 2005 23:25:40 -0500 Original-Received: from omen.defaultvalue.org (localhost [127.0.0.1]) by defaultvalue.org (Postfix) with ESMTP id 6B15B90D2B for ; Fri, 9 Dec 2005 22:23:54 -0600 (CST) Original-Received: from trouble.defaultvalue.org (omen.defaultvalue.org [192.168.1.1]) by omen.defaultvalue.org (Postfix) with ESMTP id DE4C6410E for ; Fri, 9 Dec 2005 20:23:53 -0800 (PST) Original-Received: by trouble.defaultvalue.org (Postfix, from userid 1000) id B7297411AD; Fri, 9 Dec 2005 20:23:53 -0800 (PST) Original-To: guile-devel@gnu.org In-Reply-To: <873bl13j6i.fsf@zip.com.au> (Kevin Ryde's message of "Sat, 10 Dec 2005 11:11:17 +1100") User-Agent: Gnus/5.110004 (No Gnus v0.4) Emacs/21.4 (gnu/linux) 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:5498 Archived-At: Kevin Ryde writes: >> I was also wondering about the possibilities for deadlock with the >> current code, and then what they might be with a srfi-45 force, > > Whenever arbitrary code executes in a mutex I guess there's scope for > that. srfi-45 shouldn't be inherently worse. I'm not sure either way yet. There are subtleties of srfi-45 that I still don't fully understand. If you haven't already, check out the reference implementation of force, and then the test cases. I'll probably have to wait until I feel like I understand the detailed semantics better before I can comment much. > Second block of code is with two magic "uncomputed" values, one for > normal and one for srfi-45 style lazy promises. If I understand how > they're supposed to work :-). You may have already noticed this, but I think the semantics of SRFI-45 force/delay are supposed to be a strict superset of R5RS force/delay, so in theory we might be able to have just one type of promise. -- Rob Browning rlb @defaultvalue.org and @debian.org; previously @cs.utexas.edu GPG starting 2002-11-03 = 14DD 432F AE39 534D B592 F9A0 25C8 D377 8C7E 73A4 _______________________________________________ Guile-devel mailing list Guile-devel@gnu.org http://lists.gnu.org/mailman/listinfo/guile-devel