From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Original-To: caml-list@sympa.inria.fr Delivered-To: caml-list@sympa.inria.fr Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) by sympa.inria.fr (Postfix) with ESMTPS id 237C67F8C9 for ; Tue, 19 Jan 2016 10:08:23 +0100 (CET) IronPort-PHdr: 9a23:3wP27RwNXZ1iEg7XCy+O+j09IxM/srCxBDY+r6Qd0egfIJqq85mqBkHD//Il1AaPBtWFraMbwLOM7+jJYi8p39WoiDg6aptCVhsI2409vjcLJ4q7M3D9N+PgdCcgHc5PBxdP9nC/NlVJSo6lPwWB6kO74TNaIBjjLw09fr2zQd6MyZXonLnop9X6WEZhunmUWftKNhK4rAHc5IE9oLBJDeIP8CbPuWZCYO9MxGlldhq5lhf44dqsrtY4q3wD86Fpy8kVWqz/e+E8TKdEJDUgKWE8osPx5jfZSg7awnYbGloWkwZFS1zB4RbSWo/u6Ha8sOdhjnrJdfbqRKw5DGzxp5xgTwXl3X8K Authentication-Results: mail2-smtp-roc.national.inria.fr; spf=None smtp.pra=leo@lpw25.net; spf=None smtp.mailfrom=leo@lpw25.net; spf=None smtp.helo=postmaster@out5-smtp.messagingengine.com Received-SPF: None (mail2-smtp-roc.national.inria.fr: no sender authenticity information available from domain of leo@lpw25.net) identity=pra; client-ip=66.111.4.29; receiver=mail2-smtp-roc.national.inria.fr; envelope-from="leo@lpw25.net"; x-sender="leo@lpw25.net"; x-conformance=sidf_compatible Received-SPF: None (mail2-smtp-roc.national.inria.fr: no sender authenticity information available from domain of leo@lpw25.net) identity=mailfrom; client-ip=66.111.4.29; receiver=mail2-smtp-roc.national.inria.fr; envelope-from="leo@lpw25.net"; x-sender="leo@lpw25.net"; x-conformance=sidf_compatible Received-SPF: None (mail2-smtp-roc.national.inria.fr: no sender authenticity information available from domain of postmaster@out5-smtp.messagingengine.com) identity=helo; client-ip=66.111.4.29; receiver=mail2-smtp-roc.national.inria.fr; envelope-from="leo@lpw25.net"; x-sender="postmaster@out5-smtp.messagingengine.com"; x-conformance=sidf_compatible X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A0D8BQDE/J1WnB0Eb0JehHmIVrNNAQGBbIYPAoE5PQ8BAQEBAQEBARABAQEBAQYNCQkhLkEOgV6CCAEBAwFAOgQLC0YsK4gsCK17hVqLFAEBAQcBAQEBARgGiGyCaIUjgn+BG44+iGGcYI5dOgEBAYI3FQeBeyA0g3SCegEBAQ X-IPAS-Result: A0D8BQDE/J1WnB0Eb0JehHmIVrNNAQGBbIYPAoE5PQ8BAQEBAQEBARABAQEBAQYNCQkhLkEOgV6CCAEBAwFAOgQLC0YsK4gsCK17hVqLFAEBAQcBAQEBARgGiGyCaIUjgn+BG44+iGGcYI5dOgEBAYI3FQeBeyA0g3SCegEBAQ X-IronPort-AV: E=Sophos;i="5.22,316,1449529200"; d="scan'208";a="198060367" Received: from out5-smtp.messagingengine.com ([66.111.4.29]) by mail2-smtp-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Jan 2016 10:07:50 +0100 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id 2795720BD8 for ; Tue, 19 Jan 2016 04:07:50 -0500 (EST) Received: from web3 ([10.202.2.213]) by compute4.internal (MEProxy); Tue, 19 Jan 2016 04:07:50 -0500 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=lpw25.net; h= content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-sasl-enc :x-sasl-enc; s=mesmtp; bh=phW1C8e6ej7/BTy+Y100mZgz9D8=; b=aGrbJ6 YgFBLzVNmnItlYurQQMwWMMpwWC7M73Fht9fPTraY4tjTlWk0JUOqHLuQoAQMLaj Gp6a9o+79Km/zrOBp9Ok3pK1Jt0BbfQQWF3YXdJSF2++jG48k+G7J+JOM1jhhsuV rLMiWd6bmSKxtN3TFi7MymfnLXDkxExS/yCQg= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-sasl-enc:x-sasl-enc; s=smtpout; bh=phW1C8e6ej7/BTy +Y100mZgz9D8=; b=HzUFg2nlz0ies427QWx/e8iGrE3qoqBWrM+OtA2PBnRwiHu JGenyqJYiYMkNAhb15n4iXoZV+5K4sykcTphv/U4xAZHYXlp/qt4s7d3YVn/n2MD 769ok0Ifuxxfx9sSqKSx4OCIOdLq4zgkTtq6/osS5fzDF73fRUiCS2CFavYQ= Received: by web3.nyi.internal (Postfix, from userid 99) id E33C511021F; Tue, 19 Jan 2016 04:07:49 -0500 (EST) Message-Id: <1453194469.2351553.496126650.44E1CE9C@webmail.messagingengine.com> X-Sasl-Enc: 6smOsCfA7ctmH23IEO/xZUszQLBB9RpRRQ7h1zMC6V9d 1453194469 From: Leo White To: caml-list@inria.fr MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain X-Mailer: MessagingEngine.com Webmail Interface - ajax-6cda141f In-Reply-To: References: Date: Tue, 19 Jan 2016 04:07:49 -0500 Subject: Re: [Caml-list] Data representation of records > My question is, why records need the labels. > In my comprehension, there is no chance that we check the label of records. The "label" is called the tag. Every allocated object in OCaml has a tag. They are stored in the header word and are part of the information used by the GC to traverse OCaml values (they are also used by the non-parametric polymorphic functions like "=" and "Hashtbl.hash"). Tags above a certain number have special meaning for the GC, all the rest are used for ordinary values (records, variants etc.). Records have to be given one of these ordinary tags so it might as well be 0. Regards, Leo