fn ngon! (sides, size) -> {
  repeat sides {
    forward! (size)
    right! (div (1, sides))
  }
  :tada!
}

fn randcolor () -> (random (0, 255), random (0, 255), random (0, 255))

fn pen_randcolor! () -> pencolor! (randcolor ())

fn spiral_gonr! {
  (iter) -> spiral_gonr! (iter, iter, 30)
  (_, 0, _) -> :ok
  (iter, times, size) -> {
    pen_randcolor! ()
    ngon! (4, size)
    right! (inv (iter))
    spiral_gonr! (iter, dec (times), inc (size))
  }
}
spiral_gonr! (100)