Re: Problem about imported schema type when processing XQuery

Since it does not import in-scope schema definitions from the imported modules, the importing
module should not see what schema definitions are there in the imported modules.Since they
could not see each other, then how could they decide whether their ISSD is "equivalent"?
and it seems also meaningless to compare their ISSD because they will not disturb each
other. 

 

This may be why the spec doesn't require an implementation to check that the two ISSDs are compatible, but merely says that the results are unpredictable if they are not. 

and

If a module could see the imported module's schema definition, then why spec. still
force the importing module explicitly import necessary schema definition, since these types
will surely be imported from other module's ISSD?

XSLT took the decision that all imported schema definitions would be available in all modules. However, that makes it harder to do separate compilation of modules. I think the rule in XQuery that each module must import all the schema definitions that it needs is there in the belief that this will make separate compilation of modules easier.

 

Michael Kay

http://www.saxonica.com/