structure TaskPriority = struct
  type priority = int
  val compare = Int.compare
  type item = int * real
  val priority : item -> int = #1
end
 
structure PQ = LeftPriorityQFn (TaskPriority)

val seed   = Random.rand (19,21)

val Ntasks = 100000
val Nprio  = 100

 
val _ = 
    let
        val tasks = 
            List.tabulate
                (Ntasks, 
                 fn (i) => 
                 let 
                     val prio = Int.mod (Random.randNat seed, Nprio)
                     val r  = Real.fromInt i
                 in
                     (prio, r)
                 end)
                                      
        val pq = foldl PQ.insert PQ.empty tasks
        (* or val pq = PQ.fromList tasks *)

        fun aux pq' =
            case PQ.next pq' of
                NONE => ()
              | SOME ((prio, r), pq'') => (
                  print (Int.toString prio ^ ", " ^ (Real.toString r) ^ "\n");
                  aux pq''
              )
    in
        aux pq
    end