wrapping table

t = setmetatable({}, {
    __index = function(t, i)
        return (i>#t and t[i-#t]) or (#t>i and t[#t-i]);
    end;
});

t[1] = "A";
t[2] = "B";
t[3] = "C";

for i=1,math.random(10,30) do
    math.randomseed(os.time());
    return t[i];
end;