Goat

fun rec fib n =
  match n with
  | 0 => 0
  | 1 => 1
  | n => fib (n - 1) + fib (n - 2)

fun rec fibs a b =
  a :: lazy (fibs b (a + b))

let fibStream = fibs 0 1

fun main _ =
  io {
    do! println (show (take 10 fibStream))
  }