From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: question about Qnil representation Date: Wed, 26 Oct 2022 15:01:04 -0400 Message-ID: References: <5a560265-fa81-42d2-945b-ab85d72df9e6@Spark> <5a00e93e-5f44-4865-aeeb-51f0aced9996@Spark> <87ilk6a7be.fsf@rfc20.org> <83wn8mmt49.fsf@gnu.org> <168eb4b5-40be-43dc-8501-dc9f4c65c56f@Spark> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="5523"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) Cc: Eli Zaretskii , emacs-devel@gnu.org, matt@rfc20.org To: Troy Hinckley Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Wed Oct 26 21:07:28 2022 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1onlkO-0001DR-FL for ged-emacs-devel@m.gmane-mx.org; Wed, 26 Oct 2022 21:07:28 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1onleY-0001SL-Ol; Wed, 26 Oct 2022 15:01:26 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1onleJ-00014E-5L for emacs-devel@gnu.org; Wed, 26 Oct 2022 15:01:17 -0400 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1onleH-0007V5-2W; Wed, 26 Oct 2022 15:01:10 -0400 Original-Received: from pmg2.iro.umontreal.ca (localhost.localdomain [127.0.0.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id A695480630; Wed, 26 Oct 2022 15:01:07 -0400 (EDT) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id 138BE80536; Wed, 26 Oct 2022 15:01:06 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1666810866; bh=q019Qd8eBnR/jsUMj5lLxniG6gISyhqMKvRUlZTqxwQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=SJnTIAoxPmBmSa7rug+ddbvtTfRq1kvkCybFLn5+STsG8gOfbW+tgx3ZZlrkbsZA1 1quYdggWc36GEObXTk2eLXGy5ocKC/8WWziI/RlA6BDG/BNXSxURmIIvoFQX1GG0zN EpWCs4OHdu053UMh7zRuobnkKHZm/Gmi3n3zDc30rBVdArxYNdU6qPYZXKR0pE5oqe IKZPVG0m7bFCCQDJoFMN2+VipBt4VNAkCtQGjpD63ORm0TWoh1Yw7U0/UtNVFaEh7c mDg65UsIe63PI6GF1McLQ6ADUQo+pu/kwjD/jkwhg9l82i4Dw4L5gZcwN02zmFCU4s FRYeKUJpE2pFg== Original-Received: from lechazo (lechon.iro.umontreal.ca [132.204.27.242]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id 00D7D1207BF; Wed, 26 Oct 2022 15:01:05 -0400 (EDT) In-Reply-To: <168eb4b5-40be-43dc-8501-dc9f4c65c56f@Spark> (Troy Hinckley's message of "Wed, 26 Oct 2022 12:46:39 -0600") Received-SPF: pass client-ip=132.204.25.50; envelope-from=monnier@iro.umontreal.ca; helo=mailscanner.iro.umontreal.ca X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: "Emacs-devel" Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:298576 Archived-At: > Ah, thank you. So it is not a pointer but an index. Not really: it's a pointer that's offset by just the right amount that it ends up being 0 in the case of the pointer to Qnil. Stefan