**unfoldrN** -text

*O(n)* Like unfoldr, unfoldrN builds a ByteString from a seed value. However, the length of the result is limited by the first argument to unfoldrN. This function is more efficient than unfoldr when the maximum length of the result is known.
The following equation relates unfoldrN and unfoldr:
> unfoldrN n f s == take n (unfoldr f s)
*O(n)* Like unfoldr, unfoldrN builds a ByteString from a seed value. However, the length of the result is limited by the first argument to unfoldrN. This function is more efficient than unfoldr when the maximum length of the result is known.
The following equation relates unfoldrN and unfoldr:
> fst (unfoldrN n f s) == take n (unfoldr f s)