Method lfun::_iterator_prev()

Method _iterator_prev

optional mixed _iterator_prev()

Description

Step an iterator backwards.

Calling this function after it or _iterator_next() it has returned UNDEFINED will typically cause it to restart the iteration with the last element (ie the start and end sentinel values are the same).

Returns

Returns UNDEFINED if there are no more elements in the iterator. Otherwise it may return any other value, which for convenience may be used as index and/or value in case there is no lfun::_iterator_index() and/or no lfun::_iterator_value().

Note

This function is an optional part of the iterator API and is not called directly by the runtime.

See also

iterator_prev(), lfun::_iterator_next(), lfun::_iterator_value(), lfun::_iterator_index()