Game of Life (Conway) in scala

conway.scala

object conway {

  def neighbours(p:(Int, Int)) =
    for {
      dx <- List(-1, 0, 1)
      dy <- if (dx == 0) List(-1, 1) else List(-1, 0, 1)
    } yield (dx+p._1, dy+p._2)

  def step(cells:List[(Int, Int)]) =
    cells
      .flatMap(neighbours)
      .groupBy(identity)
      .mapValues(_.size)
      .filter {
        case (t, count) => (count == 3) || (count == 2 && cells.contains(t))
      }
      .toList
      .map(_._1)

  val board = List((1, 0), (1, 1), (1, 2))

  def compute(n:Int) = Seq.iterate(board, n)(step)

  def printGame(g:List[(Int,Int)], w:Int, h:Int) =
    Seq.tabulate(w, h){ (i,j) =>
      if (g.contains((i,j))) 'X' else 'O'
    }.map(_.mkString).mkString("\n")

  def print(i:Int, w:Int = 3, h:Int = 3) = compute(i).map(x => printGame(x,w,h)).foreach(x => {println("-"*w); println(x)})
}