Bob Foster wrote:
> Unique particle attribution is normative and not optional, but not all
> processors check it correctly and some processors check it optionally.
> Of course that leads to interoperability errors, and not just around
> UPA, but that's the state of the art.
Whilst UPA assists a particular style of implementation, it kills a lot
of the expressiveness of W3C schema. It certainly prevents being able to
evolve a given schema.
It's also obvious that a processor using schema to build a code model is
able to ignore UPA and still get its work done.
So I wonder if there isn't a case for a standard schema 1.0 extension: a
flag to indicate 'this schema is valid except it violates UPA
restrictions'. It wouldn't be backwards compatible with a strictly
compliant 1.0 schema validator, but could be useful in a specific
processing domain such as Web services.
Paul
--
http://blog.whatfettle.com
