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RE: Potential new issue: PSVI considered harmful

From: Simon St.Laurent <simonstl@simonstl.com>
Date: Wed, 12 Jun 2002 16:03:51 -0400
Message-Id: <4.2.0.58.20020612155454.021b4c40@pop3.east.ora.com>
To: <www-tag@w3.org>

At 12:42 PM 6/12/2002 -0700, Dare Obasanjo wrote:
>I'm very interested in seeing coherent arguments against the usage of the 
>PSVI in XQuery and XPath 2.0 (which isn't the same thing as using W3C XML 
>Schema primitives in both languages even though that is also the case here).

XQuery has taken a stab at reducing the PSVI to something manageable, yes. 
(See [s1].)

>I recently was asked to summarize the arguments against the inclusions of 
>the PSVI in XQuery and XPath 2.0 from the XML-DEV lists[0] and although 
>there was a lot of rhetoric

There is normally a lot of rhetoric used in discussions, yes.

>  most of it boiled down to what seemed primarily to be personal dislike

Personal dislike?  That seems like you've chosen the wrong (and 
unnecessarily derogatory) adjective.  It seems to be the case that people 
dislike W3C XML Schema (or like it) for various technical and sometimes 
business reasons. (See [s2].)

>  of W3C XML Schema and worries of implementation complexity.

"Worries" is again an odd word.  It's very clear - indeed, from some of 
your own recent posts on xml-dev - that W3C XML Schema is very difficult to 
implement correctly.

>  Now given that one of the major concerns was XPath 2.0 which allows 
> implementers to use both a flexible type exception policy with fallback 
> rules[1] as well as the consideration that static typing may be optional, 
> it seems that some of the fears in the 150 - 200 posts about XPath 2.0, 
> XQuery and the PSVI may have been allayed.

If this means that schema processing is no longer required for XPath and 
XQuery, then you may have achieved a weak version (the first part) of what 
Tim was asking for in the first place:

TB> 4. Work on XQuery and other things that require a Type-Augmented Infoset
TB> must not depend on schema processing, and should not have normative
TB> linkages to any schema language specifications.

I could tolerate optional static typing provided that the specification 
provided a conformance level for implementations which simply do not 
perform static typing, schema or no schema.

[s1] - http://www.w3.org/TR/query-datamodel/
[s2] - http://www.oreillynet.com/cs/weblog/view/wlg/1528

Simon St.Laurent
"Every day in every way I'm getting better and better." - Emile Coue
Received on Wednesday, 12 June 2002 16:02:30 GMT

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