#use "A.mli"

module PrioQueue =
   struct
     type priority = int
     type char_queue = Empty | Node of priority * char * char_queue * char_queue
     exception QueueIsEmpty
     
     let empty = Empty
     let rec insert queue prio elt =
       match queue with
         Empty -> Node(prio, elt, Empty, Empty)
       | Node(p, e, left, right) ->
           if prio <= p
           then Node(prio, elt, insert right p e, left)
           else Node(p, e, insert right prio elt, left)
   end;;

module AbstractPrioQueue = (PrioQueue: CharPQueueAbs);;