Method Iterator()->_iterator_index()
- Method
_iterator_index
 optionalprotectedmixed_iterator_index()- Description
 Returns the current index, or UNDEFINED if the iterator doesn't point to any item.
If there's no obvious index set then the index is the current position in the data set, counting from
0(zero).- See also
 _iterator_value(), lfun::_iterator_index(), iterator_index()