XOM API for Processing XML with Java

[Elliotte Harold <elharo AT metalab.unc.edu>]

I've made one final change in DOMConverter, and I think this puts 
DOMConverter performance back in the ballpark of where it was in d25. 
Briefly, the convert method now keeps a stack of the indexes so it 
always knows what the current index is, even when moving back up the 
tree. Therefore it never has to call indexOf. The performance gain is 
dramatic.

It's something I've been considering for a while, but avoided out of 
fear of complexity. However, it proved much easier to implement than I 
thought. I do worry a little that this change might have introduced 
unforeseen bugs even though it passes all the DOMConverter unit tests so 
  Wolfgang and anyone else using DOMConverter, please do give it a try. 
The latest code is in CVS. If anyone needs me to build them a JAR file, 
just holler.

The new variables to manage this are completely local so there shouldn't 
 be any thread safety issues, at least not any that weren't present 
before. The extra memory usage to manage the stack (which is just an int 
array I grow as necessary, not even a java.util.Stack) is small compared 
to the combined sizes of the DOM and XOM documents so that shouldn't 
kill anybody. It's mathematically provable that any recursive algorithm 
can be rewritten in a non-recursive fashion, though in the extreme cases 
you may have to reinvent the call stack to do it. That's close to what 
I've done here. :-)

--
Elliotte Rusty Harold
elharo AT metalab.unc.edu