[masklinn]

> Haskell has typeclasses which would probably correspond to structural typing in Scala.

Nah, typeclasses are nominative typing but added post-facto (you can define a typeclass instance for a third party's type). Typeclasses are similar to Scala's traits I think (I don't know if you can add traits to a library's types though).

[jfager]

You get typeclasses in Scala via an interaction between traits and implicits. See http://www.sidewayscoding.com/2011/01/introduction-to-type-c... for a super-quick overview and a link to a more comprehensive paper.