DouKaku?

module Doukaku170 =
struct
  open System
  open System.IO
  
  type sex   = F | M | U
  
  type meal  = { Morning : string;
                 Lunch   : string;
                 Dinner  : string }
  
  type data  = { LastName  : string;
                 FirstName : string;
                 Sex       : sex;
                 Age       : int;
                 Year      : int;
                 Month     : int;
                 MealDays  : (int * meal) list }
  
  let get_datas file =
    let (|Sex|) s = if s = "F" then F else if s = "M" then M else U in
    let step_read n (r:#TextReader) =
      let buffer = Array.zero_create n in
      ignore (r.Read(buffer, 0, n));
      String.trim [' '] (new string(buffer))
    in
    { use r = new StreamReader(File.OpenRead(file)) in
      while not r.EndOfStream do
        yield { LastName  = step_read 12 r;
                FirstName = step_read 12 r;
                Sex       = (match step_read 1 r with Sex x -> x);
                Age       = Int32.Parse(step_read 3 r);
                Year      = Int32.Parse(step_read 4 r);
                Month     = Int32.Parse(step_read 2 r);
                MealDays  = [for _ in 1..31
                             -> (Int32.Parse(step_read 2 r),
                                 { Morning = step_read 500 r;
                                   Lunch   = step_read 500 r;
                                   Dinner  = step_read 500 r })] }
      done }
end;;

let _ =
  let datas = @"C:\test.txt" |> Doukaku170.get_datas |> Seq.to_list in
  printf "%A\n" (List.hd datas);;