I don't know. I have been working on a Java/Scala driver too and thinking how you could translate a scala lambda to this kind of representation It would be really cool to do

    db("tablename").filter( x => x.name == "foo" ) 

and be able to translate that to the relevant query, but I can't really think of a way without using Macros or reflection.

I was thinking maybe a path type syntax, yeah you have to use strings for your field names but this way you can wrap it in a 'get' node .. Seems to have worked well with Play! json classes

slava @ rethink here. If you didn't already you might want to join rethinkdb-dev google group (https://groups.google.com/forum/?fromgroups#!forum/rethinkdb...). We don't have Scala people, but we if you post a question we'll do the best we can to help you out!