code / tomo

   1 func ping(x:Int->[Text])
   2 	if x > 0
   3 		return ["ping: $x"] ++ pong(x-1)
   4 	else
   5 		return ["ping: $x"]
   6 
   7 func pong(x:Int->[Text])
   8 	if x > 0
   9 		return ["pong: $x"] ++ ping(x-1)
  10 	else
  11 		return ["pong: $x"]
  12 
  13 func main()
  14 	assert ping(3) == ["ping: 3", "pong: 2", "ping: 1", "pong: 0"]