exception NoOpenNonEmptyElements

type sectionTree =
   Leaf of Xml.token Stream.t
 | Node of string * (string * string) list * sectionTree list ref
;;

let rec token_stream_of_section_tree_list =
 function
    he::tl ->
     [< token_stream_of_section_tree_list tl; token_stream_of_section_tree he >]
  | [] -> [<>]
and token_stream_of_section_tree =
 function
    Leaf t -> [< t >]
  | Node (elem_name, attr_list, section_tree) ->
     Xml.xml_nempty elem_name attr_list
      (token_stream_of_section_tree_list !section_tree)
;;

let section_stack = ref [];;
let xmloutput = ref (ref []);;
let filename = ref "";;

let reset_output fname =
 filename := fname ;
 xmloutput := ref [] ;
 section_stack := []
;;

let output n =
 let xmloutput = !xmloutput in
  xmloutput := (Leaf n) :: !xmloutput
;;

let open_non_empty_element elem_name  attr_list = 
 let newxmloutput = ref [] in
  !xmloutput := (Node (elem_name, attr_list, newxmloutput)) :: !(!xmloutput) ;
  section_stack := !xmloutput :: !section_stack ;
  xmloutput := newxmloutput
;;

let close_non_empty_element () =
 match !section_stack with
    oldxmloutput::oldsection_stack ->
     xmloutput := oldxmloutput ;
     section_stack := oldsection_stack
  | _ -> raise NoOpenNonEmptyElements
;;

let print_output () =
 Xml.pp (token_stream_of_section_tree_list !(!xmloutput)) (Some !filename)
;;