_iter :: Int -> Pattern a -> Pattern a
_iter n p = slowcat $ map (\i -> (fromIntegral i % fromIntegral n) `rotL` p) [0 .. (n-1)]
_iter :: Int -> Pattern a -> Pattern a
_iter n p = slowcat $ map (\i -> (fromIntegral i % fromIntegral n) `rotL` p) [0 .. (n-1)]
_iter n p = slowcat $ map (\i -> (fromIntegral i % fromIntegral n) `rotL` p) [0 .. (n-1)]