Not sure why we are posting alternative language implementations, but here is the Scala version :). You could say that this was an exercise for me in learning 2

Not sure why we are posting alternative language implementations, but here is the Scala version :). You could say that this was an exercise for me in learning 2.8, which I am unfamiliar with. A for comprehension isn't needed because Scala already treats Strings as a sequence of characters. (Set("letters in this sentence":_* ) & Set("and this one":_* )).toSeq.sorted.reverse Or you, can take advantage of Scala's rich choice of collections. import scala.collection.immutable.TreeSet import scala.math.Ordering._ TreeSet("letters in this sentence":_* )(Char.reverse) & Set("and this one":_* ) toSeq The machinery Scala has in place to make the second example work is quite impressive, and I was pleased to see that it worked. Even though the intersection method returns a brand new set, using implicit arguments it correctly creates a set of the correct type (TreeSet) with the correct ordering function (Char.reverse), without any duplication of code in the standard library (like overriding '&' in every sub-class).