Using Nashorn for a general-purpose JavaScript AST handler?

[KARR, DAVID]

>From time to time, I've looked at using PMD for various metadata scanners for 
>Java code.  It's very easy to define callbacks for various syntax elements and 
>then gather data from those found elements.  I'm starting to see people 
>looking at doing similar things for JavaScript code.  Is there a 
>straightforward way to use Nashorn to do this kind of thing?