(2) A great challenge - and perhaps a hopeless one - would be to create an expressiveness which could at least be a far cry of what XPath offers. It is strange to say

     N.walk(Axis.child("city")).flatMap(Axis.attribute("name").map(Node::stringValue)

when what you really want to say is

     city/@name

Excellent point. However, dropping into another language does have all sorts of disadvantages: apart from the learning issues, there's the lack of compile-time syntax checking and type checking, the cost of dynamic compilation/interpretation, etc.

One thing to look at, perhaps, is how it translates into Scala, where you can define your own operators:

A.flatMap(B)   -->   A/B

A.attribute(B)  -->   A @ B

etc; and then we start to have something very XPath-like, but with a syntax that's compiled and validated by the host language.

Michael Kay

Saxonica