RE: XML Schema

> 
> Why was it [the path expression in xsd:field] so restricted and is that a
good thing in your opinion?
> 

It was restricted to a subset that can easily be evaluated in streaming
mode, that is, without building hte document tree in memory.

There's no doubt that the fact that schema validation can be done in
streaming mode increases the range of applications for which it is suitable.
There's also no doubt that some users find the resulting restrictions in
functionality frustrating.

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