XOM API for Processing XML with Java

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

John Cowan wrote:

> Elliotte Harold scripsit:
>
>
> > count(//*) | //*
>
>
> Thus spake XPath section 3.4:
>
> # An _or_ expression is evaluated by evaluating each operand and
> # converting its value to a boolean as if by a call to the _boolean_
> # function. The result is true if either value is true and false
> # otherwise. The right operand is not evaluated if the left operand
> # evaluates to true.


I think you're confusing or expressions with union expressions. An or 
expression (Production 21) would be

count(//*) or //*

What we've got here is a union expression, production 18. However, I do 
note that "The | operator computes the union of its operands, which must 
be node-sets. Predicates are used to filter expressions in the same way 
that they are used in location paths. It is an error if the expression 
to be filtered does not evaluate to a node-set" so you're right and this 
should not be an issue. Jaxen does return list objects containing the 
union of non-node-sets, but this is an error in Jaxen. I'll report it.

--
Elliotte Rusty Harold  elharo AT metalab.unc.edu
XML in a Nutshell 3rd Edition Just Published!
http://www.cafeconleche.org/books/xian3/
http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim