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RE: [XML Schema 1.1] Using doc() in xs:assert ... the referenced document needs a schema?

From: Costello, Roger L. <costello@mitre.org>
Date: Mon, 27 Apr 2009 12:03:56 -0400
To: "'xmlschema-dev@w3.org'" <xmlschema-dev@w3.org>
Message-ID: <9E51F88D5247B648908850C35A3BBB5003F245AA7B@IMCMBX3.MITRE.ORG>

Hi Michael,

> Can you provide a little more information?  Where did you discover
> these requirements?  

I discovered these "requirement" upon using SAXON. Michael Kay has since informed me that this is unique to SAXON, and is not in the specification.

> Making the 'available documents' property be the empty set helps
> ensure (a) better interoperability between validators, and (b) the
> context-independence of schema-validity assessment of an element
> or attribute against a declaration or type definition.  The
> context-independence of validation against a type is important to
> many users of XSD (although not, I suspect, to all).

I'm not clear on (b) but (a) certainly sounds like the decision to disallow doc() for cross-document validation was done to make it easier to implement 1.1 schema validators. Validators are built once, but used many times. Disallowing doc() seems to sacrifice XSD 1.1 usability in favor of ease of validator implementations.

/Roger 
Received on Monday, 27 April 2009 16:04:33 GMT

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