Subject: i31 (qdtext BNF) resolved

From: Julian Reschke <[email-masked]>
Date: Mon, 18 Jun 2007 15:31:44 +0200

Hi,

I had an outstanding action item to resolve issue i31 
(<http://www.w3.org/Protocols/HTTP/1.1/rfc2616bis/issues/#i31>) as per 
<http://www.w3.org/2007/03/18-rfc2616-minutes.html#action13>.

Done. See 
<http://www.w3.org/Protocols/HTTP/1.1/rfc2616bis/draft-lafon-rfc2616bis-latest.html#rfc.issue.i31-qdtext-bnf>.

Best regards, Julian

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From: Julian Reschke <[email-masked]>
Date: Mon, 18 Jun 2007 16:35:08 +0200

> <http://www.w3.org/Protocols/HTTP/1.1/rfc2616bis/draft-lafon-rfc2616bis-latest.html#rfc.issue.i31-qdtext-bnf>. 

Speaking of which, qdtext is now defined as:

        qdtext         = <any TEXT excluding <"> and "\">

That production will (IMHO) be rejected by both RFC822-style and 
RFC4234-style ABNF parsers (since the the first > character ends the 
prose val).

A simple fix would be to replace this by:

        qdtext         = <any TEXT excluding '"' and '\'>

We could also embrace the Core Rules of RCF4234 
(<http://greenbytes.de/tech/webdav/rfc4234.html#rfc.section.B.1>, 
defining DQUOTE and using it throughout (which should be a painless 
change, except for a few productions where we'd need to realign comments).

Feedback appreciated, Julian

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From: Julian Reschke <[email-masked]>
Date: Mon, 18 Jun 2007 18:17:57 +0200

Julian Reschke wrote:
 > ...

Collecting more ABNF related issues:

- the "_" character is not allowed in rule names; affects:

http_URL = "http:" "//" host [ ":" port ] [ abs_path [ "?" query ]]
                    | abs_path [ "?" query ]

(where http_URL is defined here, and abs_path is inherited from RFC2396)

- prose values may include line ends; affects some verbose productions 
that probably should be rewritten completely

Best regards, Julian

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From: Bjoern Hoehrmann <[email-masked]>
Date: Mon, 18 Jun 2007 18:21:52 +0200

>        qdtext         = <any TEXT excluding <"> and "\">

I would really appreciate if we can get rid of such prose rules and
instead provide a machine-readable grammar, noting such prose in a
comment if really necessary.

>RFC4234-style ABNF parsers (since the the first > character ends the 

That would also solve problems of this nature.
-- 
Björn Höhrmann · mailto:[email-masked] · http://bjoern.hoehrmann.de
Weinh. Str. 22 · Telefon: +49(0)621/4309674 · http://www.bjoernsworld.de
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From: Julian Reschke <[email-masked]>
Date: Mon, 18 Jun 2007 18:30:17 +0200

> comment if really necessary.

Yes, that's the ultimate goal.

However, I think we should be very careful while updating the ABNF. 
Therefore it would be good if we can get it into a state where an RFC822 
parser can process it first (that will allow us to parse and normalize 
the grammar, enabling proper change tracking).

> That would also solve problems of this nature.

Understood.

Best regards, Julian

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From: Lisa Dusseault <[email-masked]>
Date: Mon, 18 Jun 2007 11:27:55 -0700

If you use character ranges, then people can use Jutta's tool (http:// 
www.quut.com/abnfgen/)  to generate legal strings to test parsers with

e.g. from elsewhere:
	CHAR    = %x01-09 / %x0B / %x0C / %x0E-21 / %x22-5B / %x5D-7F

Her tool can also be used to test an ABNF writer's intuition about  
what their ABNF allows.

Lisa

On Jun 18, 2007, at 7:35 AM, Julian Reschke wrote:

>
> Julian Reschke wrote:
>> Hi,
>> I had an outstanding action item to resolve issue i31 (<http:// 
>> www.w3.org/Protocols/HTTP/1.1/rfc2616bis/issues/#i31>) as per  
>> Done. See <http://www.w3.org/Protocols/HTTP/1.1/rfc2616bis/draft- 
>> lafon-rfc2616bis-latest.html#rfc.issue.i31-qdtext-bnf>. Best  
>> regards, Julian
>
> RFC4234-style ABNF parsers (since the the first > character ends  
> the prose val).
>
> We could also embrace the Core Rules of RCF4234 (<http:// 
> greenbytes.de/tech/webdav/rfc4234.html#rfc.section.B.1>, defining  
> DQUOTE and using it throughout (which should be a painless change,  
> except for a few productions where we'd need to realign comments).
>

---

From: Julian Reschke <[email-masked]>
Date: Mon, 18 Jun 2007 23:31:29 +0200

Lisa Dusseault wrote:
> If you use character ranges, then people can use Jutta's tool 
> (http://www.quut.com/abnfgen/)  to generate legal strings to test 
> parsers with
> 
> e.g. from elsewhere:
> Her tool can also be used to test an ABNF writer's intuition about what 
> their ABNF allows.
> 
> Lisa

Lisa,

yes yes yes. We're not there yet. We're trying to *carefully* change the 
ABNF so that it can be fed into a parser. Once we have that, we'll have 
a tool that can generate a normalized version of the ABNF for the 
purpose of change tracking.

Best regards, Julian