Use List::Rotation::Cycle to loop through a list of values. Once you get to
the end of the list, you go back to the beginning.

List::Rotation::Cycle is implemented as a Singleton Pattern. You always just
get 1 (the very same) Cycle object even if you use the new method several
times. This is done by using Memoize on the new method. It returns the same
object for every use of new that comes with the same List of parameters.

WWW: http://search.cpan.org/dist/List-Rotation-Cycle/