From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Andy Wingo Newsgroups: gmane.lisp.guile.devel Subject: Re: when and unless Date: Tue, 06 Dec 2011 17:25:49 +0100 Message-ID: <877h29oeeq.fsf@pobox.com> References: <878vsjd2fh.fsf@pobox.com> <87r50ircng.fsf@pobox.com> <4EDDC8B1.3000509@gentoo.org> <87mxb6kkzx.fsf@fencepost.gnu.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: dough.gmane.org 1323188784 25508 80.91.229.12 (6 Dec 2011 16:26:24 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Tue, 6 Dec 2011 16:26:24 +0000 (UTC) Cc: guile-devel@gnu.org To: David Kastrup Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Tue Dec 06 17:26:19 2011 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1RXxqT-0005jy-RC for guile-devel@m.gmane.org; Tue, 06 Dec 2011 17:26:17 +0100 Original-Received: from localhost ([::1]:32850 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXxqT-0002HG-8H for guile-devel@m.gmane.org; Tue, 06 Dec 2011 11:26:17 -0500 Original-Received: from eggs.gnu.org ([140.186.70.92]:50387) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXxqL-0002Fj-BC for guile-devel@gnu.org; Tue, 06 Dec 2011 11:26:14 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RXxqC-0005Us-1P for guile-devel@gnu.org; Tue, 06 Dec 2011 11:26:09 -0500 Original-Received: from a-pb-sasl-sd.pobox.com ([74.115.168.62]:64575 helo=sasl.smtp.pobox.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXxq7-0005Tl-3t; Tue, 06 Dec 2011 11:25:55 -0500 Original-Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTP id 665727610; Tue, 6 Dec 2011 11:25:54 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=3pHKzTE6ReoWgjZHwev4bGTnsxk=; b=LuAiS3 r0UsH0r30cjIYfIaBRPMcqu0K1p9IO+GwN+defdEQVXWvlBmQlUUtUXWW/c5jcbT OFKsCBeJjU0/rHgDYNX70KoX07am+K2Touf+sLFOtIjlnNUCtYFma/X+0DugZoyd r57Z6ouuLHk7nPKq5FbMHEqqvOvcV6+8OOv+8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; q=dns; s=sasl; b=lSDExBNdmgvCH/qrzILKxA3p5+N8AzZR DTwdqg+7TW7Qa6XOWUiihqIJP9my39fsiyacuT4cfchOB4lEcagQObmqT+IhP4I/ nabheAFstCowStW5AA4cFxLuTlTDtY1cbfwWS7WIIqJmm6IjCnZLOazj8d2vbPyu F/7XeXQqmlA= Original-Received: from a-pb-sasl-sd.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTP id 58595760E; Tue, 6 Dec 2011 11:25:54 -0500 (EST) Original-Received: from badger (unknown [90.164.198.39]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTPSA id 9797A760B; Tue, 6 Dec 2011 11:25:53 -0500 (EST) In-Reply-To: <87mxb6kkzx.fsf@fencepost.gnu.org> (David Kastrup's message of "Tue, 06 Dec 2011 12:17:06 +0100") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) X-Pobox-Relay-ID: F7E5CB32-2026-11E1-8FEB-65B1DE995924-02397024!a-pb-sasl-sd.pobox.com X-detected-operating-system: by eggs.gnu.org: Solaris 10 (beta) X-Received-From: 74.115.168.62 X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.14 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 Original-Sender: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.devel:12990 Archived-At: On Tue 06 Dec 2011 12:17, David Kastrup writes: > I've actually wondered if it would not make sense to return > *unspecified* in the case of the plain else-less if even if the > condition is true, namely when you write (if #t #t). I have wondered this too. > There is probably code relying on this to be #t, but frankly, this > appears like a recipe for breakage. Yeah. A first (and probably worthwhile) step would be to warn if such a statement is processed for value. Warning on one-armed ifs in tail position of a function would be harder, as you would have to analyze the call sites of the function. Regards, Andy -- http://wingolog.org/