Hi Andy and Dave:

thank you for incorporating the Law of Demeter into your book and 
your articles.

We have implemented a LoD checker in AspectJ:

http://www.ccs.neu.edu/research/demeter/biblio/LoD-Checkers-2002.html

A few years ago we have improved the LoD: we improved:
"any directly held component object" to
"any part object (whether it is stored or computed)"

Computed part objects are returned by self calls.
This makes the LoD more useful and well rounded.

Best regards,
-- Karl