type 'a llist = LNil | LCons of 'a * (unit -> 'a llist);;

let rec lfrom k = LCons (k, function () -> lfrom (k+1));;

let rec ltake = function
  	(0, _) -> []
  | (_, LNil) -> []
  | (n, LCons(x,xf)) -> x::ltake(n-1, xf())
;;
ltake (4,lfrom 7);; (* - : int list = [7; 8; 9; 10] *)

(* 1 *)
let rec lpolacz(ll1, ll2) =
	match ll1 with
	  LCons(x, xt) -> LCons(x, fun()-> lpolacz(ll2, xt()))
	| LNil when ll2<>LNil -> lpolacz(ll2, ll1)
	| _ -> LNil

ltake(10, lpolacz(lfrom(1), lfrom(11)));;
ltake(22, lpolacz(lfrom(-10), lfrom(0)));;
ltake(10, lpolacz(lfrom(0), LNil));;
ltake(10, lpolacz(LNil, lfrom(-10)));;
ltake(10, lpolacz(LNil, LNil));;

let rec polacz(l1, l2) =
	match l1 with
		h::t -> h::polacz(l2,t)
	| [] when l2<>[] -> polacz(l2,l1)
	| _ -> []

polacz([1;3;5;7;9;11], [2;4;6;8;10])
polacz([2;2], [1;1;1;1])
polacz([], [])
polacz([1;2;3], [])
polacz([], [4;5;6])

(* 2 *)
let mulListToLazy l x =
	let rec mul = function
			[] -> LNil
		| h::t -> LCons(h*x, function()-> mul t)
	in mul l;;

mulListToLazy [2;3;4;2;3;4] 10;;
mulListToLazy [66; 2; 2332] 2;;
ltake(5, (mulListToLazy [2;3;4;5;6;7;8;9;10] 10));;
ltake(3, mulListToLazy [1;2;3;4;5] (-1));;


//3
def cGeo(a:Int, iloraz:Int)=
  {
      def geoH(a1:Int, q:Int):Stream[Int] =
      {
        println(a1)
        a1#::geoH(a1*q, q)
      }
      geoH(a, iloraz)
  }

 cGeo(2, 2)
 cGeo(10, (-1)).take(5)
 cGeo(10, (-1)).take(5) toList
 cGeo(2, 2).take(7) toList