@rotate(t:tab, n:int)


build a new tab which contains the elements of t circularly shifted by n. If n is positive the element are right shifted, else they are left shifted.

       @rotate([1, 2, 3, 4], -1) == [2, 3, 4, 1]
@rotate([1, 2, 3, 4], 1) == [4, 1, 2, 3]