Generating all possible combinations from a List[List[Int]] in Scala

Question

Given the following list:

List(List(1,2,3), List(4,5))

I would like to generate all the possible combinations. Using yield, it

Answer 1

Ezekiel has exactly what I was looking for. This is just a minor tweak of it to make it generic.

  def generateCombinations[T](x: List[List[T]]): List[List[T]] = {
    x match {
      case Nil => List(Nil)
      case h :: _ => h.flatMap(i => generateCombinations(x.tail).map(i :: _))
    }
  }