xlang/test/fib.x

main() : int {
  i := 0;
  while i < 10 {
    print fib_rec(i);
    print fib_iter(i);
    i = i + 1;
  }
}

fib_rec(n : int) : int {
  if n < 2 {
    return 1;
  }
  return fib_rec(n - 1) + fib_rec(n - 2);
}

fib_iter(n : int) : int {
  x0 := 1;
  x1 := 1;
  i := 0;
  while i < n {
    t := x0 + x1;
    x0 = x1;
    x1 = t;
    i = i + 1;
  }
  return x0;
}