From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Mark H Weaver Newsgroups: gmane.lisp.guile.devel Subject: Re: Immediate doubles (up to 2^256) and rationals coming to Guile 3 Date: Tue, 11 Jun 2019 07:34:08 -0400 Message-ID: <87tvcw73uc.fsf@netris.org> References: <87zhmvaw5p.fsf@netris.org> <87o939b2lz.fsf@gnu.org> <87a7eqae8d.fsf@netris.org> <87d0jk5xdh.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="47428"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) Cc: Andy Wingo , guile-devel To: Ludovic =?utf-8?Q?Court=C3=A8s?= Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Tue Jun 11 14:09:49 2019 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hafay-000C9h-OT for guile-devel@m.gmane.org; Tue, 11 Jun 2019 14:09:44 +0200 Original-Received: from localhost ([::1]:56860 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hafax-0000mA-NH for guile-devel@m.gmane.org; Tue, 11 Jun 2019 08:09:43 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:52976) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hafB3-0007js-By for guile-devel@gnu.org; Tue, 11 Jun 2019 07:43:00 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1haf4s-0007AM-Gt for guile-devel@gnu.org; Tue, 11 Jun 2019 07:36:35 -0400 Original-Received: from world.peace.net ([64.112.178.59]:41626) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1haf4s-00078i-DX; Tue, 11 Jun 2019 07:36:34 -0400 Original-Received: from mhw by world.peace.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1haf4o-0004uD-Fh; Tue, 11 Jun 2019 07:36:30 -0400 In-Reply-To: <87d0jk5xdh.fsf@gnu.org> ("Ludovic \=\?utf-8\?Q\?Court\=C3\=A8s\=22'\?\= \=\?utf-8\?Q\?s\?\= message of "Tue, 11 Jun 2019 10:39:38 +0200") X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 64.112.178.59 X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.23 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" Xref: news.gmane.org gmane.lisp.guile.devel:19962 Archived-At: Ludovic Court=C3=A8s writes: > Though an immediate, like a fixnum or an iflo, is still something > different from a tagged heap object like a pair, right? I should clarify that in this new approach, a pair is *not* a tagged heap object. Tagged heap objects are those which have a tag in their first word. In this new approach, pairs are not tagged in this sense, and it is no longer possible to distinguish a pair from a non-pair by looking at their raw heap blocks. Tagged heap objects (thobs) have 000 in the low 3 bits of the SCM. Pairs have 0110 in the low 4 bits of the SCM. Regards, Mark