OCaml 入門。Lesson 5。http://try.ocamlpro.com/

l5.ml

(* Step 4 *)
let xy =
  let x = 'x' and y = 'y' in x :: [y]

let ab =
  let a = 'a' and b = 'B' in a :: [Char.lowercase b]

let up = Char.uppercase in
  let big_xy = List.map up xy and
  big_ab = List.map up ab in
  big_ab @ big_xy

(* Step 5 *)
if 1 + 2 = 3 then (
  print_string "1 + 2 =\n";
  print_string "3!!!!!!\n"
);;

if 1 + 2 = 3 then begin
  print_string "1 + 2 =\n";
  print_string "3!!!!!!\n"
end

(* Step 6 *)
(* double 3 + 2 = (double 3) + 2*)
let ten =
  let double x = x+x in
  double (3 + 2)

let hundred =
  if true || false then (
    print_string "May I help you?\n" ;
    100
  ) else 0

let one =
  let accum = ref (-54) in
  for i = 1 to ten do accum := !accum + i done ;
  !accum

one + match hundred with
  | 42  -> (match ten with 10 -> 52  | _ -> 0)
  | 100 -> (match ten with 10 -> 110 | _ -> 0)
  | _ -> -1