IETF Logo Mail Archive

Re: [vwrap] ECMA-262 and the Real LLSD type

Meadhbh Hamrick <ohmeadhbh@gmail.com> Thu, 06 May 2010 19:38 UTC

Return-Path: <ohmeadhbh@gmail.com>
X-Original-To: vwrap@core3.amsl.com
Delivered-To: vwrap@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 054B93A6C19 for <vwrap@core3.amsl.com>; Thu, 6 May 2010 12:38:21 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.247
X-Spam-Level:
X-Spam-Status: No, score=-2.247 tagged_above=-999 required=5 tests=[AWL=0.352, BAYES_00=-2.599]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id V0lXdt-+5TGL for <vwrap@core3.amsl.com>; Thu, 6 May 2010 12:38:20 -0700 (PDT)
Received: from mail-qy0-f197.google.com (mail-qy0-f197.google.com [209.85.221.197]) by core3.amsl.com (Postfix) with ESMTP id D4E253A6C15 for <vwrap@ietf.org>; Thu, 6 May 2010 12:38:19 -0700 (PDT)
Received: by qyk35 with SMTP id 35so445829qyk.15 for <vwrap@ietf.org>; Thu, 06 May 2010 12:38:03 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:mime-version:received:in-reply-to :references:from:date:message-id:subject:to:cc:content-type :content-transfer-encoding; bh=btWjWuTe36N1l9thmVwb9eei2DKFtiCP+w6wKDCBW8U=; b=qHCIYH2Os1BuBlK9yVyw/p0wh5IeTXzRn8+n7uCKjvhzhgqin2v96cw28ssfSAY6gh 9sBoXR9jzy1Bstc9qfT7FgRCZ8DEQWVoPbSRLU1o8q64ceKXxJsuIXlPnuyHTZ5nQrcD imty0R+U+C/6FV8CFG3auzHTQRGx3o2gyJb1Q=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=xTFx0cy39fY/9/MM5kSAHLQUkDO7OuilwNQ8n2fc0BQfWRxgWNO38tuLNbDxc2B6xF DCCngXoBGighzdYOWKTNWb3hgimpgIbzqHMBZ38jf63pq2F43mvxNaBiXkzWvfNSQX77 yZTrZSDXnP9MdKSdEg8tLzqGHxxzb3HRzaJL0=
Received: by 10.229.231.144 with SMTP id jq16mr4208183qcb.53.1273174683242; Thu, 06 May 2010 12:38:03 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.229.24.142 with HTTP; Thu, 6 May 2010 12:37:43 -0700 (PDT)
In-Reply-To: <62BFE5680C037E4DA0B0A08946C0933DCE425A2C@rrsmsx506.amr.corp.intel.com>
References: <62BFE5680C037E4DA0B0A08946C0933DCE425A2C@rrsmsx506.amr.corp.intel.com>
From: Meadhbh Hamrick <ohmeadhbh@gmail.com>
Date: Thu, 6 May 2010 12:37:43 -0700
Message-ID: <z2jb325928b1005061237q9c08d062v25e43996c964839f@mail.gmail.com>
To: "Hurliman, John" <john.hurliman@intel.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
Cc: "vwrap@ietf.org" <vwrap@ietf.org>
Subject: Re: [vwrap] ECMA-262 and the Real LLSD type
X-BeenThere: vwrap@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: Virtual World Region Agent Protocol - IETF working group <vwrap.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/vwrap>, <mailto:vwrap-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/vwrap>
List-Post: <mailto:vwrap@ietf.org>
List-Help: <mailto:vwrap-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/vwrap>, <mailto:vwrap-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 06 May 2010 19:38:21 -0000

k. so i pinged doug crockford about it. his response was that JSON
wants to be independent of any floating point standard, and thus only
represents finite numbers.

so... a) it's not a mistake or an oversight that you can't represent
NaNs as JSON-Numbers and b) even if it somehow worked in current
implementations, it's not the intent of the JSON designers, so, it may
not work in the future.

so do we know how important it is to represent each of the distinct
non-finite reals?

-cheers
-meadhbh
--
meadhbh hamrick * it's pronounced "maeve"
@OhMeadhbh * http://meadhbh.org/ * OhMeadhbh@gmail.com



On Thu, May 6, 2010 at 10:36 AM, Hurliman, John <john.hurliman@intel.com> wrote:
> In draft-hamrick-llsd-00 "3.2. JSON Serialization" it states:
>
>   Real  LLSD 'Real' values are represented by the JSON non-terminal 'number'.
>
> Then later in "Appendix A. ABNF of Real Values" it lists a series of strings that can be converted into real values:
>
>   negative-infinity =  %x2D.49.6E.66.69,6E.69.74.79   ; "-Infinity"
>   negative-zero     =  %x2D.5A.65.72.6F               ; "-Zero"
>   zero              =  %x30.2E.30                     ; "0.0"
>   positive-zero     =  %x2B.5A.65.72.6F               ; "+Zero"
>   positive-infinity =  %x2B.49.6E.66.69,6E.69.74.79   ; "+Infinity"
>   signaling-nan       =  %4E.61.4E.53                   ; "NaNS"
>   quiet-nan         =  %4E.61.4E.51                   ; "NaNQ"
>
> Does this mean that an LLSD real type with a value of -Infinity needs to be converted to a JSON string, and would be decoded on the receiving side as an LLSD string with value "-Infinity" (that happens to have a valid conversion to an LLSD real)? ECMA-262 does not support Infinity, NaN, etc. for the JSON 'number' type so it looks like we need to transmit those values as strings.
>
> John
> _______________________________________________
> vwrap mailing list
> vwrap@ietf.org
> https://www.ietf.org/mailman/listinfo/vwrap
>

v2.8.7 | Report a Bug | By Email