From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Marius Vollmer Newsgroups: gmane.lisp.guile.bugs Subject: Re: bug in eqv? Date: 22 Mar 2006 01:52:40 +0200 Message-ID: <87acbjs6d3.fsf@minimini.mvo.home> References: <20060318034255.6DF6E1B77C9@home.voluntocracy.org> <87mzfkd36j.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 1142985184 23976 80.91.229.2 (21 Mar 2006 23:53:04 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Tue, 21 Mar 2006 23:53:04 +0000 (UTC) Cc: bug-guile@gnu.org, Aubrey Jaffer Original-X-From: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Wed Mar 22 00:53:00 2006 Return-path: Envelope-to: guile-bugs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1FLqen-00084Y-Ao for guile-bugs@m.gmane.org; Wed, 22 Mar 2006 00:52:57 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1FLqex-000365-MZ for guile-bugs@m.gmane.org; Tue, 21 Mar 2006 18:53:07 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1FLqer-00034x-Rt for bug-guile@gnu.org; Tue, 21 Mar 2006 18:53:01 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1FLqen-00034I-Ex for bug-guile@gnu.org; Tue, 21 Mar 2006 18:52:58 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1FLqen-00034F-8B for bug-guile@gnu.org; Tue, 21 Mar 2006 18:52:57 -0500 Original-Received: from [213.243.153.36] (helo=smtp3.pp.htv.fi) by monty-python.gnu.org with esmtp (Exim 4.52) id 1FLqeq-00086c-OE for bug-guile@gnu.org; Tue, 21 Mar 2006 18:53:00 -0500 Original-Received: from zagadka.ping.de (cs181072157.pp.htv.fi [82.181.72.157]) by smtp3.pp.htv.fi (Postfix) with SMTP id CDCC427AC66 for ; Wed, 22 Mar 2006 01:52:40 +0200 (EET) Original-Received: (qmail 32709 invoked by uid 1000); 22 Mar 2006 01:52:40 +0200 Original-To: Kevin Ryde In-Reply-To: <87mzfkd36j.fsf@zip.com.au> Original-Lines: 28 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4 X-BeenThere: bug-guile@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Bug reports for GUILE, GNU's Ubiquitous Extension Language" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Errors-To: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.bugs:3219 Archived-At: Kevin Ryde writes: > Aubrey Jaffer writes: > > > > Because (= 0.0 -0.0) is #t, (eqv? 0.0 -0.0) must be #t. > > Ah dear, thanks. Bit too much creativity with the nans and infs. Hmm. I think SRFI 77 (Preliminary Proposal for R6RS Arithmetic) would require (eqv? 0.0 -0.0) => #f, since it says The eqv? procedure returns #f if obj1 and obj2 yield different results (in the sense of eqv?) when passed as arguments to any other procedure that can be defined as a finite composition of Scheme's standard arithmetic procedures. and, for example, (eqv? (flatan2 -1.0 -0.0) (flatan2 1.0 -0.0)) => #f. See also "Lucier's Proposal" in the SRFI 77 document. I originally copied the behavior of PLT Scheme and I'd say it is OK to follow SRFI 77 for the behavior of negative zero, infinities and NaNs now that it exists. (We get (integer? +inf.0) => #f wrong, then, and probably other things.) -- GPG: D5D4E405 - 2F9B BCCC 8527 692A 04E3 331E FAF8 226A D5D4 E405 _______________________________________________ Bug-guile mailing list Bug-guile@gnu.org http://lists.gnu.org/mailman/listinfo/bug-guile