open Parser;;
letter;;
digit;;
test;;
test letter "hello";;
test letter "!!!";;
digit;;
test digit "123";;
sat;;
sat (fun c -> c = 'a');;
test (sat (fun c -> c = 'a')) "asd";;
test (sat (fun c -> c = 'a')) "bsd";;
eoi;;
test eoi "test";;
test eoi "";;
oneof;;
(oneof "abc");;
test (oneof "abc") "asd";;
test (oneof "abc") "test";;
(digit <|> letter);;
test (digit <|> letter) "asd123";;
test (digit <|> letter) "123qwe"";;
test (digit <|> letter) "123qwe";;
test (digit <|> letter) "!!";;
test (digit <|> letter <|> oneof "?!") "!!";;
(digit >>= fun d1 -> digit >>= fun d2 -> return (d1, d2));;
test (digit >>= fun d1 -> digit >>= fun d2 -> return (d1, d2)) "1234";;
test (digit >>= fun d1 -> digit >>= fun d2 -> return [d1; d2]) "1234";;
let rec count_spaces = 
  (space >>= fun i -> return (i+1)) <|>
let rec count_spaces = 
  (space >> count_space >>= fun i -> return (i+1)) <|>
  (any >> count_spaces >>= fun i -> return i) <|>
  (eoi >> return 0);;
let rec count_spaces = 
  (space >> count_spaces >>= fun i -> return (i+1)) <|>
  (any >> count_spaces >>= fun i -> return i) <|>
  (eoi >> return 0);;
let rec a = a;;
let rec a () = a ();;
let rec count_spaces () = 
  (space >> count_spaces () >>= fun i -> return (i+1)) <|>
  (any >> count_spaces () >>= fun i -> return i) <|>
  (eoi >> return 0);;
test (count_spaces ()) "bla bla";;
let rec count_spaces () =
  (space >>= fun _ -> count_spaces () >>= fun i -> return (i+1)) <|>
  (any >>= fun _ -> count_spaces () >>= fun i -> return i) <|>
  (eoi >> return 0);;
test (count_spaces ()) "bla bla";;
test (count_spaces ()) "bla b asd as daq ew la";;
test (many space) "   qwe";;
test (space) "   qwe";;
type arith = Num of int | Add of arith * arith | Mul of arith * arith;;
let n = many1 digit >>= fun r -> return (Num (int_of_string (Strng.to_string r)));;
test n "123";;
let rec e () =
  t () >>= e'
and e' term = (char '+' >>= fun _ -> t () >>= e' >>= fun t2 -> return (Add (term, t2))) <|> return term
and t () = f () >>= t'
and t' fact = (char '*' >>= fun _ -> f () >>= t' >>= fun f2 -> return (Mul (fact, f2))) <|> return fact
and f () = (char '(' >>= fun _ -> e () >>= fun e1 -> char ')' >> return e1;;
let rec e () =
  t () >>= e'
and e' term = (char '+' >>= fun _ -> t () >>= e' >>= fun t2 -> return (Add (term, t2))) <|> return term
and t () = f () >>= t'
and t' fact = (char '*' >>= fun _ -> f () >>= t' >>= fun f2 -> return (Mul (fact, f2))) <|> return fact
and f () = (char '(' >>= fun _ -> e () >>= fun e1 -> char ')' >> return e1) <|> n;;
test eoi "";;
test (e ()) "3+2*5";;