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Re: WSDL 1.1 schema question

From: Arthur Ryman <ryman@ca.ibm.com>
Date: Wed, 26 Mar 2003 10:21:41 -0500
To: "Sanjiva Weerawarana" <sanjiva@watson.ibm.com>
Cc: "Jeffrey Schlimmer" <jeffsch@windows.microsoft.com>, www-ws-desc@w3.org, www-ws-desc-request@w3.org
Message-ID: <OF00478AFF.E7A6F05B-ON85256CF5.0053799C@torolab.ibm.com>

I agree that schema ain't good enough. The spec expresses many additional 
semantic rules that are beyond the scope of XSD. For example, AFAIK, XSD 
can't express semantics involving imported WSDL documents.

I would like to see the WG define a schema that expresses as much as 
possible and give that schema "official" status. That is what I meant by 
the schema being normative, i.e. that it is an official part of the spec. 
The schema is not exhaustive though, since it can't express everything.

The approach for the extra-schema semantics should be that the WG include 
test assertions in the spec. A WSDL validator could then implement the 
test assertions. The combination of the normative XSD plus all the test 
assertions should define what it means for WSDL to be WSDL-valid.

We therefore have a sequence of checks we can perform on WSDL:

1. Syntax - well formed XML
2. Structure - XSD valid wrt to the normative wsdl.xsd
3. Semantic - all test assertions in the spec are satisfied

So to really acheive the needed level of precision, we need both a 
normative XSD and a normative set of test assertions.

Arthur Ryman

"Sanjiva Weerawarana" <sanjiva@watson.ibm.com>
Sent by: www-ws-desc-request@w3.org
03/26/2003 10:02 AM

        To:     "Jeffrey Schlimmer" <jeffsch@windows.microsoft.com>, Arthur 
        cc:     <www-ws-desc@w3.org>
        Subject:        Re: WSDL 1.1 schema question


I agree in concept, of course. However, in practice the XSD would 
have to have way more flexibility than really legal due to XSD
limitations. Those would have to be documented in annotations,
meaning that XSD validation simply ain't good enough. 

In that setting, I'm not so sure making the XSD normative is
very useful or accurate.

What does our resident schema expert think?


----- Original Message ----- 
From: "Jeffrey Schlimmer" <jeffsch@windows.microsoft.com>
To: "Arthur Ryman" <ryman@ca.ibm.com>
Cc: <www-ws-desc@w3.org>
Sent: Wednesday, March 26, 2003 1:03 AM
Subject: RE: WSDL 1.1 schema question

> +1
> > From: Arthur Ryman [mailto:ryman@ca.ibm.com]
> > As a tool developer, I find the second class status of the schema to
> be a
> > bad idea. After all, schema is a precise formal language that supports
> > machine processing. My goal as a WG member is that we should provide a
> > normative schema since that is unambiguous in comparison with the
> narative
> > prose in the spec.
Received on Wednesday, 26 March 2003 10:21:51 UTC

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