pi.util.Number.range(from (optional),to);
>>>pi.util.Number.range(0,5);
[0,1,2,3,4]
>>> pi.util.Number.range(5);
[0,1,2,3,4]
>>> pi.util.Number.range(3,8);
[3,4,5,6,7]
>>> pi.util.Number.range(3,8,function(i){ return i*2 });
[6, 8, 10, 12, 14]