// Learn more about F# at http://fsharp.org
// See the 'F# Tutorial' project for more help.
type instruction =
    | ADD
    | SUB
    | MUL
    | SQR
    | DIV
    | PUSH of int

type stack = int list

exception BadExpression 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
    | DIV, a::b::ys -> try (b / a) :: ys with
                       | :? System.DivideByZeroException -> printf "HI"; ys
    | PUSH x, ys -> x :: ys
    | _, _ -> raise (BadExpression (x, y))

let wypiszInstr = function
    | ( PUSH x ) -> " PUSH " + System.Convert.ToString(x)
    | ( SQR ) -> " SQR "
    | ( ADD ) -> " ADD "
    | ( SUB ) -> " SUB "
    | ( MUL ) -> " MUL "

exception ZlyStos of (instruction list)

let intpProg (is) =
    let rec iPS = function
            | ([], x::xs) -> x
            | (i::is, xs) -> try iPS(is, intInstr(i, xs)) with BadExpression (x, y) ->
                                                               (
                                                                   printfn "Pozostale elementy stosu: %A" is
                                                                   1
                                                               )
    iPS(is, [])

[<EntryPoint>]
let main argv =
    printfn "%A" <| intpProg ([DIV])

    0 // return an integer exit code