Amazon shows that there are four books (in English) about EAGLE. One dates from 2003, one from last year (2013), one from earlier this month (April 2014), and one yet to be released (May 2014).
From the reviews and promo material, it seems that all four of these books are oriented towards the new user. Only one of them (Designing Circuit Boards with EAGLE by Matt Scarpino, April 2014) seems to even acknowledge scripting and user language programs.
Does anyone have experience with any of these books?