let x = 3
let y = 4
let () =
  Printf.printf
    "%d + %d = %d\n"
    x y (x + y)


let add x y = x + y


let rec fact n =
  if n = 1 then 1
  else n * fact (n - 1)


  add x y
  (add x) y


let add_five = add 5
let six = add_five 1


let hi x = printf "Hi, %s!\n" x
let hi = printf "Hi, %s!\n"


List.iter (Printf.printf "- %s\n") ["foo"; "bar"]


let (|>) x f = f x


["foo"; "bar"]
|> List.map String.uppercase
|> List.iter
   (Printf.printf "- %s\n")


let to_string x =
  match x with
  | 1 -> "one"
  | 2 -> "two"
  | n -> string_of_int n


let to_string = function
  | 1 -> "one"
  | 2 -> "two"
  | n -> string_of_int n


type download_result =
  | Success of filepath
  | Network_error of string
  | Aborted_by_user


match download url with
| Success file -> process file
| Network_error msg -> alert msg
| Aborted_by_user -> ()


type program = {
  name : string;
  homepage : url option;
}


type 'a result =
  | Success of  'a
  | Error of exn


let success = function
  | Success value -> value
  | Error ex -> raise ex


let () =
  match ask "Automatic?" with
  | `yes -> automatic ()
  | `no -> manual ()


ocaml prog.ml


ocamlbuild prog.native


true: warn(A), strict_sequence


opam install lablgtk


package(lablgtk2, lablgtk2.auto-init)


ocamlbuild -use-ocamlfind


type stock_item = {
  id : stock_id;
  mutable location : position;
}


let total = ref 0 in
for i = 1 to 10 do
  total := !total + i
done;
Printf.printf
  "Total = %d\n" !total


ocamlbuild -use-ocamlfind db.inferred.mli