X-Mozilla-Status: 0001
X-Mozilla-Status2: 00000000
Delivered-To: barryleiba.mailing.lists@gmail.com
Received: by 10.58.181.71 with SMTP id du7csp44943vec;
        Wed, 6 Aug 2014 12:01:00 -0700 (PDT)
X-Received: by 10.70.92.132 with SMTP id cm4mr12808770pdb.151.1407351660409;
        Wed, 06 Aug 2014 12:01:00 -0700 (PDT)
Return-Path: <abnf-discuss-bounces@ietf.org>
Received: from mail.ietf.org (mail.ietf.org. [2001:1900:3001:11::2c])
        by mx.google.com with ESMTPS id gp6si1530452pac.212.2014.08.06.12.00.59
        for <multiple recipients>
        (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
        Wed, 06 Aug 2014 12:01:00 -0700 (PDT)
Received-SPF: pass (google.com: domain of abnf-discuss-bounces@ietf.org designates 2001:1900:3001:11::2c as permitted sender) client-ip=2001:1900:3001:11::2c;
Authentication-Results: mx.google.com;
       spf=pass (google.com: domain of abnf-discuss-bounces@ietf.org designates 2001:1900:3001:11::2c as permitted sender) smtp.mail=abnf-discuss-bounces@ietf.org;
       dkim=pass header.i=@ietf.org
Received: from ietfa.amsl.com (localhost [IPv6:::1])
	by ietfa.amsl.com (Postfix) with ESMTP id 711971B283B;
	Wed,  6 Aug 2014 12:00:36 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ietf.org; s=ietf1;
	t=1407351636; bh=HP1g+Id+T0WnxjG2LB92OasO7Z6mokdd8YaUbdR6S6o=;
	h=Message-ID:Date:From:MIME-Version:To:References:In-Reply-To:Cc:
	 Subject:List-Id:List-Unsubscribe:List-Archive:List-Post:List-Help:
	 List-Subscribe:Content-Transfer-Encoding:Content-Type:Sender;
	b=sX9APdotF3mivWS276CShxndmyabpzPjXanxZbYsl8jDaiN2Ix62beeBYyQFwyrhS
	 yJn0FaT0WPuH2gWSrLe3MMVB+t0762aj89fqnkcQLoaYKBs9AES/A4A/rDmTStVytm
	 9LUBejLvFXwi3p/E5YoB0uAupLWJ9GRjF2rfTYGA=
X-Original-To: abnf-discuss@ietfa.amsl.com
Delivered-To: abnf-discuss@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1])
 by ietfa.amsl.com (Postfix) with ESMTP id A35E41B289B
 for <abnf-discuss@ietfa.amsl.com>; Wed,  6 Aug 2014 12:00:29 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.235
X-Spam-Level: 
X-Spam-Status: No, score=-1.235 tagged_above=-999 required=5
 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1,
 SPF_SOFTFAIL=0.665] autolearn=no
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 NHmm4bO7ha0I for <abnf-discuss@ietfa.amsl.com>;
 Wed,  6 Aug 2014 12:00:28 -0700 (PDT)
Received: from qmta06.westchester.pa.mail.comcast.net
 (qmta06.westchester.pa.mail.comcast.net [IPv6:2001:558:fe14:43:76:96:62:56])
 by ietfa.amsl.com (Postfix) with ESMTP id 7F1F71A005E
 for <abnf-discuss@ietf.org>; Wed,  6 Aug 2014 12:00:24 -0700 (PDT)
Received: from omta02.westchester.pa.mail.comcast.net ([76.96.62.19])
 by qmta06.westchester.pa.mail.comcast.net with comcast
 id bVW21o0050QuhwU56X0Qmp; Wed, 06 Aug 2014 19:00:24 +0000
Received: from Paul-Kyzivats-MacBook-Pro.local ([50.138.229.164])
 by omta02.westchester.pa.mail.comcast.net with comcast
 id bWvN1o00K3ZTu2S3NWvNWd; Wed, 06 Aug 2014 18:55:23 +0000
Message-ID: <53E27A1A.10609@alum.mit.edu>
Date: Wed, 06 Aug 2014 14:55:22 -0400
From: Paul Kyzivat <pkyzivat@alum.mit.edu>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7;
 rv:24.0) Gecko/20100101 Thunderbird/24.6.0
MIME-Version: 1.0
To: Ned Freed <ned.freed@mrochek.com>
References: <53E26154.8020308@alum.mit.edu>
 <01PB24L5SC060000SM@mauve.mrochek.com>
In-Reply-To: <01PB24L5SC060000SM@mauve.mrochek.com>
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net;
 s=q20140121; t=1407351624;
 bh=A+mKxlVMwsmqghFlTxTexe/DxEn8iCsIEul5t8PP5KQ=;
 h=Received:Received:Message-ID:Date:From:MIME-Version:To:Subject:
 Content-Type;
 b=MNRwANUxihpxg+V1YR+RvSIB3ZsFpukWzI9ADE0sN3fbteQuPQyBlBUoXuE+VLK3j
 dqBhC6Btmd0S5P8vtdjOhl7wyJosgWuSE+3x/xpzbIML6AVEJ2gIb8tEhf8fqC8IPw
 C0ycdZn5EPjqHXR5cefvejzJYnD5+1SG/rZWNxN+2acS3MbO/InHVko4u0fsA+oyBq
 gK0/2Gw/Nmq9oYIsVj0SGOtXZHZpq0f3HkLPKQY1Bd0IxMW2IB4vRrTd5fTxn8SH3T
 Py1/BaHB7n6Q3VwTTpxElgZqblXeSJY8fFqgCoTgDqMaMTF9nRZWF2RuVNE9ZQuhUh
 Dm2dDDPv5/3KQ==
Archived-At: http://mailarchive.ietf.org/arch/msg/abnf-discuss/wr0MdPYnUDDXQBXdlu9bDLi6eco
Cc: "abnf-discuss@ietf.org" <abnf-discuss@ietf.org>
Subject: Re: [abnf-discuss] Case-sensitive string constants in ABNF?
X-BeenThere: abnf-discuss@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: "General discussion about tools,
 activities and capabilities involving the ABNF meta-language"
 <abnf-discuss.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/abnf-discuss>,
 <mailto:abnf-discuss-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/abnf-discuss/>
List-Post: <mailto:abnf-discuss@ietf.org>
List-Help: <mailto:abnf-discuss-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/abnf-discuss>,
 <mailto:abnf-discuss-request@ietf.org?subject=subscribe>
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Errors-To: abnf-discuss-bounces@ietf.org
Sender: "abnf-discuss" <abnf-discuss-bounces@ietf.org>

On 8/6/14 2:29 PM, Ned Freed wrote:
>> Has there ever been consideration of supporting case-sensitive string
>> constants in ABNF?
>
>> While the case-insensitive ones are more often than not what is needed,
>> some protocol designs have places where case-sensitivity is desired. It
>> is possible to accomplish this now, using numeric byte values. But it is
>> hard, both to read and to write.
>
> Agreed.
>
>> I see no *technical* problem with supporting both kinds. The only
>> questions are:
>> - Is it a good idea to support both? (Or is *not* supporting them
>>    intentional, to discourage case-sensitive syntaxes?)
>
>> - What syntax to use in ABNF to denote the two types, while remaining
>>    backward compatible.
>
>> Regarding the syntax, a straightforward approach would be to define
>> case-sensitive strings using a new delimiter. Single quote is a likely
>> candidate since it is currently unused.
>
> It's the obvious thing, but I worry it will be confusing.

Yeah, it worries me too. People are already confused about quoted 
strings being case insensitive.

>> Another possibility for syntax would be to allow an optional prefix on
>> char-val. For example: %S"abc", %I"abc".
>
> I like the idea of using prefixes. I don't especially care about the
> syntax.

I like the concept. It puts the choice in your face without being overly 
inconvenient. And the % syntax seems to fit in well with what is there.

But it isn't obvious what type indicator characters to use to denote 
case sensitivity and the converse. The %S and %I were the first things 
that came to mind, but I don't love them.

It also occurred to me that there might be other string modifiers that 
people might want. E.g., unicode. Once you get to unicode it might not 
make sense to talk about case-insensitive comparison.

	Thanks,
	Paul

_______________________________________________
abnf-discuss mailing list
abnf-discuss@ietf.org
https://www.ietf.org/mailman/listinfo/abnf-discuss