XOM API for Processing XML with Java

["Michael Kay" <mike AT saxonica.com>]

> > 
> > List<Node>    XPath.selectNodeSequence("*")
> > Node          XPath.selectNode("..")
> > double        XPath.selectDouble("count(*)")
> > String        XPath.selectString("name(..)")
> > boolean       XPath.selectBoolean("name(..) = 'banana')
> 
> This is just where Java's string-typedness mismatches with XSLT's 
> weak-typedness. This isn't bad. I am worried that selectNode and 
> selectNodeSequence blow up when the expression returns a 
> String/double/boolean.
> 
> The complexity of it worries me, especially when you do 
> consider XPath 2 
> where there are many more types that might be returned.

Yes, it's not ideal. 

Alternative B is to do what Saxon does in its "internal" interfaces: an
XPath 2.0 expression returns List<Item>, Item subclasses into Node and
AtomicValue, AtomicValue subclasses into IntegerValue, StringValue,
BooleanValue and the rest, and StringValue wraps a String, BooleanValue
wraps a boolean, and so on.

Alternative C is to return List<Object> where the Object may be a String, a
Node, a Boolean, etc, and the user has to sort it out.

Michael Kay