type check_status = Checked | Unchecked;;

let hashtable = Hashtbl.create 17;;

let get_term_and_type_checking_info uri =
 try
  Hashtbl.find hashtable uri
 with
  Not_found -> 
   let filename = Getter.get uri in
    let term = TheoryParser.theory_of_xml filename in
     Hashtbl.add hashtable uri (term, Unchecked) ;
     (term, Unchecked)
;;


let get_theory uri =
 fst (get_term_and_type_checking_info uri)
;;

let is_type_checked uri =
 match snd (get_term_and_type_checking_info uri) with
    Checked   -> true
  | Unchecked -> false
;;

let set_type_checking_info uri =
 match Hashtbl.find hashtable uri with
  (term, _) ->
   Hashtbl.remove hashtable uri ;
   Hashtbl.add hashtable uri (term, Checked)
;;