RE: building a hierarchical classification out of flat

> Then i changed the match attribute to 
> "x/document" and erased the "s" of "deep-equals". When i run 
> this with saxon, i get a list of errors, beginning with 
> "Exception in thread 'Thread-25'
> java.lang.StackOverflowError at
> net.sf.saxon.functions.DeepEqual.deepEquals(DeepEqual.java:186)".

As you can tell, I have problems remembering whether that function name has
a final "s" or not...

The stack overflow looks like some simple error in the recursion, or it
might be due to a cycle in the data. Programming tree traversals is a lot
more complicated if you have to check for cycles as you go. (And the example
in my book that attempts it is embarrassingly wrong.)

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