> > It's really a DOM-style implementation, and the namespace 
> > axis just goes 
> > up the tree and gathers up the nodes.  So, this breaks when 
> > you really on 
> > generate-id() as a hack to implement node identity, and also 
> > in the case, 
> > where you use the parent axis.  In the first case, there's no 
> > work-around, 
> > while in the second case, there is.
> > 
> 
> Saxon, as a matter of interest, does exactly the same thing internally, 
but
> when you use the namespace axis explicitly it creates a transient 
namespace
> node with the right parent pointer. This is sufficiently rare that the 
cost
> hardly matters.

My initial intention was to do the same thing in Xalan-C.  However, I was 
worried that tracking the lifetime of the nodes would be expensive.  Also, 
having transient nodes could affect API users because they would end up 
with node-sets containing nodes that were not in the initial source tree 
and had a potentially different lifetime.

I'm just happy that XPath 2.0 has given implementers the wiggle room to 
get rid of namespace nodes altogether.

Dave