type instruction  =
       | ADD                (* dodawanie   *)
       | SUB                (* odejmowanie *)
       | MUL                (* mnozenie    *)
       | SQR                (* podnoszenie do kwadratu *)
       | PUSH of float     (* odkladanie na stos *)

type stack = float list

exception BLEDNY_PROGRAM of (instruction * stack)
let intInstr (x , y) =
    match  x , y  with
    | ADD, a::b::ys -> (b + a) :: ys : stack
    | SUB, a::b::ys -> (b - a) :: ys
    | MUL, a::b::ys -> (b * a) :: ys
    | SQR, a::ys -> (a * a) :: ys
    | PUSH x, ys -> x::ys
    | _ , _ -> raise  (BLEDNY_PROGRAM(x, y));

let wypisz_instr = function
     | ( PUSH x) -> "PUSH " + System.Convert.ToString(x)
     | ( SQR )   -> " SQR "
     | ( ADD )   -> " ADD "
     | ( SUB )   -> " SUB "
     | ( MUL )   -> " MUL ";
let intpProg(is) =
  let rec iPS = function
          | ([],x::xs) -> x  (* koniec listy instrukcji (obliczeń)
                                zwracany wierzchołek stosu         *)
          | (i::is, xs) -> iPS(is, intInstr(i, xs))
                             (* wykonanie pojedynczej instrukcji i *)
  iPS(is,[])                 (* start programu, stos początkowo pusty *)
[<EntryPoint>]
let main argv =
    let il1 = [PUSH 3.0; PUSH 4.0; ADD; PUSH 2.0; MUL];
    let il2 = [PUSH 2.0; PUSH 3.0; ADD; PUSH 4.0];
    let il3 = [PUSH 1.0; PUSH 2.0; ADD; MUL];
    let stos:stack = []
    let stos1 =  intInstr(PUSH 3.0,stos);
    let stos2 =  try intInstr(ADD, stos1) with BLEDNY_PROGRAM (a, b) ->( printf "Wyjątek: Błędne wykonanie programu\nOperand: %A, Stos: %A" a b ; b);
    let w1 = intpProg(il1)
    let w2 = intpProg(il2)
    //let w3 = intpProg(il3)
    printfn "%A" argv
    printfn "stos1: %A " <| (stos1)
    printfn "stos2: %A " <| (stos2)
    printfn "intprog: %A" <| (w1)
    printfn "intprog: %A" <| (w2)
    //printfn "intprog: %A" <| (w3)



    printf "Naciśnij klawisz..."
    ignore (System.Console.ReadKey(true))
    0 // return an integer exit code