RE: [xml-dev] RE: Difference between "normalize" and "canonicalize"?

["Michael Kay" <mike@saxonica.com>]

> Because the semantics of the schema language used, W3C Schema 
> 1.0, are not rich enough to express all of the constraints 
> for XSLT as an XML vocabulary.  I believe the RELAX-NG schema 
> semantics are rich enough.

I don't think Relax-NG is rich enough to describe XPath expressions or XSLT
patterns as a data type. So you will only ever describe a subset of the
constraints.

Also, there's a fuzzy boundary between syntactic constraints and semantic
constraints (like: you can't call a template that hasn't been defined.). Any
schema language can define all the syntactic constraints if you define
"syntactic constraint" to mean "a constraint that can be expressed in the
schema", and deem everything else to be semantic.

Michael Kay
http://www.saxonica.com/