How to make a nested toSet in scala in an idiomatic way?

Question

Is there a more idiomatic way to change a nested sequence of sequences into a nested set of sets?

def toNestedSet[T](tsss: Seq[Seq[Seq[T]]]): Set[Set[Set[T]]]  = 
   tsss.map(_.map(_.toSet).toSet).toSet

Is it possible to implement a function which would work with lists of any depth?

Answer 1

To address the second part of your question (processing a list of arbitrary depth), something like this would work (type erasure gets in the way a bit):

  def toNestedSet(ts: Seq[Any]): Set[Any] = {
    ts.foldLeft[Set[Any]](Set())((acc, b) => b match {
        case s: Seq[_] => acc + toNestedSet(s)
        case x => acc + x
    })
  } 

Note: quick and dirty -- it works, but fairly easy to break :)

Edit: The cast was redundant