Tests foldLeft and foldRight of List in Scala.

tests.sc

package streams

object tests {

  def xtoy(x: Int, y: List[Int]): List[Int] = {
		println(x + " @ " + y)
		x :: y
	}
	
	def ytox(x: List[Int], y: Int): List[Int] = {
		println(y + " @ " + x)
		y :: x
	}
	
	val l = List.range(1, 11)
	val r = List(100, 200, 300)
	
	// y = r, x = l(n) from right to left
	l.foldRight(r)(xtoy)
                                                  
	// x = r, y = l(n) from left to right
	l.foldLeft(r)(ytox)

}