RE: [xml-dev] Separate data from rules ... is the XML Schema 1.1 <assert

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

> 
> What is a "structural rule?"
> 
> In XML Schema 1.0 the answer was clear: anything that 
> required computation, if-then-else logic, inference, and 
> co-constraints could not be placed in XML Schema, and was 
> therefore placed in Schematron) All rules were expressed and 
> managed by Schematron.

No, I think that's post-hoc rationalisation. I don't think the split between
structural rules and business rules equates at all closely to the split
between grammar and predicates. You can say in XSD that a manager must have
at least five employees, which is definitely a business rule (and a bad
one); but it takes Schematron to say that a paragraph cannot appear nested
within another paragraph unless there is an intervening table, which is in
my book a structural rule - if indeed there is a black-and-white
distinction, which I doubt. The world is fuzzy.

Regards,

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