ocaml

hello_ocaml.ml

type 'a myList = MyNil | MyCons of 'a * 'a myList
let myList x y = MyCons (x, MyCons(y, MyNil))
let rec map f x = 
  match x with
  | MyNil -> MyNil
  | MyCons (x, xs) ->
    MyCons (f x, map f xs)

let rec foreach f x =
  match x with
  | MyNil -> ()
  | MyCons (x, xs) -> 
    f(x);
    foreach f xs

let () = foreach print_string (myList "xxx" "vvv")

let assert_and_dump a e = let _ = print_int(a) in assert (a == e)
let rec repeat f n x = if n > 0 then repeat f (n -1) (f x) else x

let fib n = 
  let f = fun (a, b) -> (a + b , a) in 
  let (fibn, _) = repeat f n (0 , 1)
  in fibn

let () = assert_and_dump (fib 0) 0

let curry f x y = f (x, y)

let uncurry f (x, y) = f x y

let f (x, y) = x * y
let () = print_int (curry f 1 2)
let () = print_int (uncurry (curry f) (2, 3))

(* let () = print_int (4/0) *)

let rec find x = function 
  | [] -> None
  | a :: l when a = x -> Some 1
  | _ :: l -> match find x l 
      with 
      | Some i -> Some (i+1)
      | None -> None 

let () = match find 1 [1; 2; 3] with
  | Some i -> print_int(i)
  | None -> print_string("not_found")


let () = print_int(2);print_newline()