## Iterative fibonacci function.

def fib(n)
  res = []
  a = 0; b = 1
  for _ in 0..n
    list_append(res, a)
    temp = a; a = b; b += temp;
  end
  return res
end

fibs = fib(10)
print('fibs =', fibs)
assert(fibs == [0, 1, 1, 2, 3, 5, 8, 13, 21, 34])