Could one not say that 'schema' languages that have less expressiveness, are easier to apply? Provided there are no ambiguities. I mean if a schema language doesn't for instance support nullability, that a particular element/attrib simply isn't allowed to be null, right?
Grtz > -----Oorspronkelijk bericht----- > Van: [email protected] [mailto:[email protected]] Namens > Michael Kay > Verzonden: dinsdag 6 maart 2012 9:41 > Aan: [email protected] > Onderwerp: Re: [xquery-talk] Schema in xquery > > On 06/03/2012 02:27, David Lee wrote: > > I've been contemplating the relationship between schema and type in schema > aware xquery. > > Is xquery strictly tied to XSD? That is, could an implementation support > another schema format such as rng to provide for the type system? > It would be possible to support a different schema language, but not > without difficulty. > > (a) XSD is the only schema language I know of that defines how elements > and attributes in the instance document are associated with types, and > that includes constraints (such as the notorious UPA) to make this > association unambiguous. > > (b) Many of the concepts of XSD, such as the distinction between simple > and complex types, substitution groups, and nullability, turn up in the > semantics of XQuery, and would need to be mapped to the concepts of a > different schema language. > > Michael Kay > Saxonica > > > _______________________________________________ > [email protected] > http://x-query.com/mailman/listinfo/talk _______________________________________________ [email protected] http://x-query.com/mailman/listinfo/talk
