cartesian-product.scala

#!/bin/bash

exec /opt/scala-2.10/bin/scala -feature "$0" "$@"
!#
class CartesianProduct(product: Traversable[Traversable[_ <: Any]]) {
  override def toString(): String = {
    product.toString
  }

  def *(rhs: Traversable[_ <: Any]): CartesianProduct = {
      val p = product.flatMap { lhs =>
        rhs.map { r =>
          lhs.toList :+ r
        }
      }

      new CartesianProduct(p)
  }
}

object CartesianProduct {
  def apply(traversable: Traversable[_ <: Any]): CartesianProduct = {
    new CartesianProduct(
      traversable.map { t =>
        Traversable(t)
      }
    )
  }
}

val aoeu = CartesianProduct(Set(0, 1))
val snth = Set(2, 3)
val htns = Set(4, 5)

println(aoeu * snth * htns)