IETF Logo Mail Archive

Re: [precis] Enforcement as an Idempotent operation

Peter Saint-Andre <stpeter@stpeter.im> Mon, 27 February 2017 00:48 UTC

Return-Path: <stpeter@stpeter.im>
X-Original-To: precis@ietfa.amsl.com
Delivered-To: precis@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 13B4C12957F for <precis@ietfa.amsl.com>; Sun, 26 Feb 2017 16:48:48 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.7
X-Spam-Level:
X-Spam-Status: No, score=-2.7 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=stpeter.im header.b=OThVP5bT; dkim=pass (1024-bit key) header.d=messagingengine.com header.b=L4xb/fND
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id PE30SOQTNV2p for <precis@ietfa.amsl.com>; Sun, 26 Feb 2017 16:48:47 -0800 (PST)
Received: from new1-smtp.messagingengine.com (new1-smtp.messagingengine.com [66.111.4.221]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 2DABF129494 for <precis@ietf.org>; Sun, 26 Feb 2017 16:48:47 -0800 (PST)
Received: from compute2.internal (compute2.nyi.internal [10.202.2.42]) by mailnew.nyi.internal (Postfix) with ESMTP id 8924FA8E8; Sun, 26 Feb 2017 19:48:46 -0500 (EST)
Received: from frontend2 ([10.202.2.161]) by compute2.internal (MEProxy); Sun, 26 Feb 2017 19:48:46 -0500
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=stpeter.im; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc:x-sasl-enc; s=mesmtp; bh=bJlWuW3664ZzNAt cw1ZOrr7NxBo=; b=OThVP5bTc1HWB+zq6MUH9hsDutbM/d0p8iACuAcP0NQQQd0 LYlOuYdmeqzLHZ7F5cMPMe1qVzYgiB6q6KQaSOUhQP4GgmMuvpZ5EI/NZDI90DUa aniLSBZif5wk5PN2STr+VUh6xiibsjj8+9TlwPXeGXckBErZalQY7Nsp7958=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc:x-sasl-enc; s= smtpout; bh=bJlWuW3664ZzNAtcw1ZOrr7NxBo=; b=L4xb/fNDUzTjMu2MyX+P +9+BaqfkRgrqF3J/eM/FKiF4T1hpiw//FGUrC99lAdKZ99rnxqT8mBMjh4isKmhX BtsjhHTEAPMoj5T4IQ+FlH4ZuMnJIwxTNoe4PwYuoZ/ipPa5sJqxgRC8UFSVMzyq S2RkvQBpFSSwhCAOpWMjWqA=
X-ME-Sender: <xms:bnezWC8gHjerHZyJqbE8oFO9xblZwKFS9LwRF7phF8kyZERdfcgfdA>
X-Sasl-enc: uqmckvi5YptvxY1wppdijAT+ya5P4yOeWVsyWVFGMiIi 1488156526
Received: from aither.local (unknown [76.25.4.24]) by mail.messagingengine.com (Postfix) with ESMTPA id D2ACD240CA; Sun, 26 Feb 2017 19:48:45 -0500 (EST)
To: William Fisher <william.w.fisher@gmail.com>
References: <CAHVjMKHVvmS6jty3-jwnnuqy-xdw-xY2j+5ExLRr6tXCMRbC2Q@mail.gmail.com> <f9b49a96-2189-bccd-5dc0-a4dc8146cbcc@stpeter.im> <CAHVjMKEVTOCV68OTfXnXhWKiXT798m2osGkwHVRhw4Cs0RLw0w@mail.gmail.com> <15c31273-c278-af61-2a01-0b68ab8af182@stpeter.im> <CAHVjMKHXL_gHrQ1+jC2T4VrJj5n+mRB5j7iD7kGHc06wpq+PEA@mail.gmail.com>
From: Peter Saint-Andre <stpeter@stpeter.im>
Message-ID: <0f5b55f8-5fcb-2a61-435e-7b93d2d8f9e6@stpeter.im>
Date: Sun, 26 Feb 2017 17:48:45 -0700
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:45.0) Gecko/20100101 Thunderbird/45.7.1
MIME-Version: 1.0
In-Reply-To: <CAHVjMKHXL_gHrQ1+jC2T4VrJj5n+mRB5j7iD7kGHc06wpq+PEA@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/precis/c_ojJ4krnhm0aJRgyd8wHEIajW4>
Cc: precis@ietf.org
Subject: Re: [precis] Enforcement as an Idempotent operation
X-BeenThere: precis@ietf.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: Preparation and Comparison of Internationalized Strings <precis.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/precis>, <mailto:precis-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/precis/>
List-Post: <mailto:precis@ietf.org>
List-Help: <mailto:precis-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/precis>, <mailto:precis-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 27 Feb 2017 00:48:48 -0000

On 2/13/17 12:04 AM, William Fisher wrote:
> On Sun, Feb 12, 2017 at 12:27 PM, Peter Saint-Andre <stpeter@stpeter.im> wrote:
>> Did you mean U+212A (KELVIN SIGN)? That decomposes to U+004B (LATIN CAPITAL
>> LETTER K).
>>
>>> The full example is:
>>> "\U0001f11aevin" => "(K)evin" => "(k)evin"
> 
> I'm talking about 'PARENTHESIZED LATIN CAPITAL LETTER K' (U+1F11A).
> Sorry it's not clear that the A is part of the unicode escape.

Thanks for the clarification.

> With casefold or tolower, the result is the same for these Nicknames:
> 
> Not idempotent: "\U0001f11A" => "(K)" => "(k)"
> Not idempotent: "\U0001f13A" => "K" => "k"
> Not idempotent: "\u210c" => "H" => "h"
> Not idempotent: "\u210d" => "H" => "h"
> Not idempotent: "\u20a8" => "Rs" => "rs"
> 
> When you apply the comparison steps from RFC 7700, Section 2.4, you
> still get something that is upper case. If you apply the comparison
> steps again, you now get lower case.

I see what you mean. I'm now leaning toward moving the case mapping rule
after the normalization rule, but first I want to think about the
implications for all of the PRECIS profiles (e.g., when using NFC vs.
using NFKC). If we go down this road, we will also want to describe the
reasoning in Section 5.2.3 of 7564bis.

Peter

v2.8.7 | Report a Bug | By Email