select :: Eq s => Zipper s a -> Zipper s a
select z
  | ((length zeroVisitsChildren) > 0) = (Zipper
                                            (fst zeroVisitsChildren)
                                            (Breadcrumb (fst zeroVisitsChildren) (fst (splitAt ((elemIndex (fst zeroVisitsChildren) childs) - 1)))
                                                                                 (snd (splitAt ((elemIndex (fst zeroVisitsChildren) childs)))))
                                            (zipperGen z))
  | otherwise = z
  where childs = (treeChildren (zipperTree z))
        zeroVisitsChildren = [t | t <- childs, (treeVisits t == 0)]