/// <summary>
/// interate through range.
/// </summary>
/// <returns> tail </returns>
public override IEnumerator <Item> iterator()
{
// XXX life is getting hard...
if (_size != 0)
{
ResultSequence newtail = ResultSequenceFactory.create_new();
for (; _start <= _end; _start++)
{
newtail.add(new XSInteger(new System.Numerics.BigInteger(_start)));
}
newtail.concat(_tail);
_tail.release();
_tail = newtail;
_size = 0;
_start = 0;
_end = 0;
}
return(_tail.iterator());
}