val element_by_tag : Naive_tree.t -> QNameSet.t -> Tree.NodeKind.t -> Bitvector.t
(** [element_by_tag t tag] returns all the nodes whose tag equal to [tag] in the tree [t]. *)
val element_by_tag : Naive_tree.t -> QNameSet.t -> Tree.NodeKind.t -> Bitvector.t
(** [element_by_tag t tag] returns all the nodes whose tag equal to [tag] in the tree [t]. *)