module type TRIP =
    sig
        type trip;;
        val create_trip : int -> int -> trip list -> trip list
        val delete_trip : int -> trip list -> trip list
        val list_trip : int -> trip list -> trip list

    end

module Trip : TRIP =
    struct
        type trip = (int * int);;
        let rec create_trip digit speed listy = (digit, speed)::listy;;
        let rec delete_trip index listy = [];;
        let rec list_trip n = function
            | (digit, speed)::tail -> Printf.printf "%d %d\n" digit speed; (digit, speed)::(list_trip n tail)
            | [] -> []
    end;;

let rec matcher = function
    | str -> match (List.hd (Str.split (Str.regexp "[ \t]+") str)) with
        | "create" -> Printf.printf "create\n"
        | "delete" -> Printf.printf "delete\n"
        | "list" -> Printf.printf "list\n"
        | _ -> Printf.printf "WTF bro\n"
;;

let rec debugger = function
    | head::tail -> Printf.printf "%s\n" head; debugger tail
    | [] -> []
;;

(* let lines = ref [] in
try
  while true; do
    lines := (matcher (read_line ())) :: !lines
  done; !lines
with End_of_file ->
  debugger (List.rev !lines) ;; *)

type mytype = Trip.trip list;;

let read_lines name : Trip.trip list =
let ic = open_in name in
let try_read () =
    try Some  (matcher (read_line ())) with End_of_file -> None in
let rec loop acc = match try_read () with
    | Some s -> loop (s :: acc)
    | None -> close_in ic; List.rev acc in
  loop []