module Prelude =
    external ll_putint      : int -> ()
    external ll_print_bool  : bool -> ()
    external ll_print_line  : ()  -> ()
    external ll_print_space : ()  -> ()

    let printInt x = ll_putint x
    let printNl = ll_print_line
    let printSpace = ll_print_space
    let printnInt x =
        printInt x
        printNl ()

    let printBool b = ll_print_bool b

open Prelude

type Vec = { x : int; y : int }
type Mat2x2 = { r1 : Vec; r2 : Vec }

class Pow 'a where
    one  : () -> 'a
    mult : 'a -> 'a -> 'a

instance Pow int where
    let one () = 1
    let mult x y = x * y

instance Pow Vec where
    let one () = { x = 1; y = 1 }
    let mult (l : Vec) (r : Vec) =
        { l with x = l.x * r.x
                 y = l.y * r.y
        }

let rec pow x n =
    if n = 0
    then one ()
    elif n = 1
    then x
    else mult x (pow x (n - 1))

class Print 'a where
    print : 'a -> ()

instance Print int where
    let print x = printInt x

instance Print Vec where
    let print (v : Vec) =
        printInt v.x
        printSpace ()
        printInt v.y

let printN x =
    print x
    printNl ()

let _ =
    printN (pow 2 10)
    printN (pow { x = 2; y = 2} 10)