JS Recursion vs Trampoline

recursion.coffee

countDown = (n) ->
  console.log(n)
  if n > 0
    countDown(n-1)
  else
    console.log('DONE!')

countDown(1000000)

trampoline.coffee

countDown = (n) ->
  console.log(n)
  if n > 0
    () -> countDown(n-1)
  else
    console.log('DONE!')

trampoline = (fun, num) ->
  result = fun(num)
  while typeof result is 'function'
    result = result()
  result

trampoline(countDown, 1000000)