Re: [Gen-art] Genart last call review of draft-ietf-httpapi-link-template-02

Mark Nottingham <mnot@mnot.net> Sat, 20 May 2023 12:43 UTC

Return-Path: <mnot@mnot.net>
X-Original-To: gen-art@ietfa.amsl.com
Delivered-To: gen-art@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 64FC1C15199D; Sat, 20 May 2023 05:43:26 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.797
X-Spam-Level:
X-Spam-Status: No, score=-2.797 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_ZEN_BLOCKED_OPENDNS=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, URIBL_DBL_BLOCKED_OPENDNS=0.001, URIBL_ZEN_BLOCKED_OPENDNS=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=mnot.net header.b="ix3iicpO"; dkim=pass (2048-bit key) header.d=messagingengine.com header.b="m6hqSvau"
Received: from mail.ietf.org ([50.223.129.194]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5Orn1mTgN4UX; Sat, 20 May 2023 05:43:21 -0700 (PDT)
Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id EA4F9C15154E; Sat, 20 May 2023 05:43:20 -0700 (PDT)
Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id C567E5C00EB; Sat, 20 May 2023 08:43:19 -0400 (EDT)
Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Sat, 20 May 2023 08:43:19 -0400
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mnot.net; h=cc :cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:sender:subject:subject:to:to; s=fm2; t= 1684586599; x=1684672999; bh=boYqd7Q/QWJmTxv/UcK5wOQMXYVbGwnVgsI EggPGF7w=; b=ix3iicpOxfu95SYmQx6FgkNLvexfgzHEr3KRnOIEefmIzSea8eH 9hhzPkG+4B1ipL2HIT+qx5w1gmyjQTaELrUr7ITilvHClsxjhw7ovkiu40pzUD5i JuIHDeR/K9HZjAJGx3kuHvzkbatYOaKsHa8tXY2+Nv9ylnL2rGMfAuIp88FoJ44e VdzlK4qIgUYZnhOvts1DzBa8yLD2UpfTCBEhT+BfZ3AsKu0KrdqieyUUzfxf/lrE JHZVp5GV9ZUTk/tffq+yIDcKmHz7ozWXhPpxmAuETj7LL103m53lAO36j5YeNzw4 5cToFyvCdJaUTQ3COzJH+2k2mtHq03V1nAw==
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:sender:subject:subject:to:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t= 1684586599; x=1684672999; bh=boYqd7Q/QWJmTxv/UcK5wOQMXYVbGwnVgsI EggPGF7w=; b=m6hqSvauAq55CDD3XZF36DvnyjMCdyfj8Ue2ri/U5i3Hg1rEEjR OAqsDfG00522EvbxxO7ngapk7/GeIIJuDv/1k/AjA0F56m2LKALyW6BOijqGYTN5 X7jqcdzAInxgrRtJtuJxB2Ixfe20NT5YeVXlsM5yH7SpzNzXQUhpwSCYULogTXx0 vnp76Cu3+FgGWIUWa7CHBPz3y03OZNCYtw8Mfk1LGH1QVSu9biz6zz/riXt9nI0U g0bCK//shi2GsYV6ed1ctfPWjRQO5nnXhweXcFwpQCd/Vomh14BO3Uf0BI7U/HHn Y2tsg5WEgPzEiiVrjpskf+nL+bAFVLlkR7Q==
X-ME-Sender: <xms:Z8BoZGNd2S6xVABa_MgHfvrlu3xLKHuUt79mJy5_vZZ98nu2gKTDaw> <xme:Z8BoZE_RrXW-2R2nFwzyF8HkSuBWXlhhmxN_LE46iBfzSLXWHfQiQOb7EvkxLiTir AFJtiqVRtNHnFrTUw>
X-ME-Received: <xmr:Z8BoZNRwQ7MsY2N0pqFQdcDaC51_qDNyftdrUw7ewxabeHpUr_AKUFExEGXxQiVLemoW>
X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrfeeijedgheefucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurheptggguffhjgffvefgkfhfvffosehtqhhmtdhhtddvnecuhfhrohhmpeforghr khcupfhothhtihhnghhhrghmuceomhhnohhtsehmnhhothdrnhgvtheqnecuggftrfgrth htvghrnheptddtgefgueevtddugfdtkeffudegveetffegjeelhfdvtedvueejteegueeg teetnecuffhomhgrihhnpehmnhhothdrnhgvthenucevlhhushhtvghrufhiiigvpedtne curfgrrhgrmhepmhgrihhlfhhrohhmpehmnhhothesmhhnohhtrdhnvght
X-ME-Proxy: <xmx:Z8BoZGvuaAu3NRin1jpyvzDn2Y8-yL7klRw0NgizNahk2AMkwTOe4A> <xmx:Z8BoZOdpyfJ9Jf9vsGaQz8_6AvJwfqh8nrzHeXMPC1gasbOC63ODEw> <xmx:Z8BoZK09wsjAWdH9ugTQLnr3TMKTYTvVjVkL5IxmGZFp1FnFkoSddQ> <xmx:Z8BoZPos6-jdZ69W1ITBtZkdev8KbZdlwMVTMhPgwrnBVJ6rOvOLyA>
Feedback-ID: ie6694242:Fastmail
Received: by mail.messagingengine.com (Postfix) with ESMTPA; Sat, 20 May 2023 08:43:17 -0400 (EDT)
Content-Type: text/plain; charset="us-ascii"
Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3731.500.231\))
From: Mark Nottingham <mnot@mnot.net>
In-Reply-To: <HE1PR07MB4441C788DC81233E50441297937C9@HE1PR07MB4441.eurprd07.prod.outlook.com>
Date: Sat, 20 May 2023 20:43:15 +0800
Cc: "gen-art@ietf.org" <gen-art@ietf.org>, HTTP APIs Working Group <httpapi@ietf.org>, Last Call <last-call@ietf.org>
Content-Transfer-Encoding: quoted-printable
Message-Id: <EE952FBC-B0A4-4818-A288-1B320B469D5E@mnot.net>
References: <168424064858.44084.3692769234533396629@ietfa.amsl.com> <34AA44A9-B351-4798-8920-90724F600D8D@mnot.net> <HE1PR07MB4441A4329BA51DC42C9796DE937C9@HE1PR07MB4441.eurprd07.prod.outlook.com> <C5848939-4628-4760-B1B7-ECB7105B866A@mnot.net> <HE1PR07MB4441C788DC81233E50441297937C9@HE1PR07MB4441.eurprd07.prod.outlook.com>
To: Christer Holmberg <christer.holmberg@ericsson.com>
X-Mailer: Apple Mail (2.3731.500.231)
Archived-At: <https://mailarchive.ietf.org/arch/msg/gen-art/yjWmL8zHSWJXWh9jgclW99Jn3nU>
Subject: Re: [Gen-art] Genart last call review of draft-ietf-httpapi-link-template-02
X-BeenThere: gen-art@ietf.org
X-Mailman-Version: 2.1.39
Precedence: list
List-Id: "GEN-ART: General Area Review Team" <gen-art.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/gen-art>, <mailto:gen-art-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/gen-art/>
List-Post: <mailto:gen-art@ietf.org>
List-Help: <mailto:gen-art-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/gen-art>, <mailto:gen-art-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sat, 20 May 2023 12:43:26 -0000

Hi Christer,

> On 20 May 2023, at 2:58 am, Christer Holmberg <christer.holmberg@ericsson.com> wrote:

[...]

>> Ah. The reason is that allowing any type would require creating a mapping of 
>> current values to SF types, and there
>> are just too many potential (and undocumented) values already in use to do 
>> this.
> 
> I don't think that is true. Just because the Parameter syntax allows values to 
> be encoded sf-string, sf-token, sf-boolean etc it doesn't mean that you have 
> to map each value (existing or new ones) to each of those encodings. If a 
> value is defined as a String, then it has to be encoded as a sf-string.

Consider an implementation that wants to serialise a link relation that has a 'foo' Parameter that it has no special knowledge of. If the value is "bar", that's very straightforward -- it will successfully serialise as a Token. However, consider the value "1.2.3.4" -- it will fail parsing, because it looks like an Integer or Decimal to the parser, but it isn't. 

Of course, we could specify something like "try to parse it as a Structured Value; if serialisation fails, serialise it as a String." That strategy might be workable, but it creates a lot of complexity -- at runtime when you have to test the value by running code, and when values are handled, because now they could come in multiple forms.

Always serialising as a string recognises that, from the standpoint of the Link header field, the value's type is opaque.


> Having said that, I'm fine with having the restriction, because in reality I 
> assume the values always will have to be encoded as sf-strings anyway (you 
> can't encode a URI as a sf-integer, sf-boolean etc).

Ok.

Cheers,

--
Mark Nottingham   https://www.mnot.net/