{ 
type result = Int of int 
              | Float of float
              | String of string 
}
let digit = ['0'-'9']
let digits = digit +
let lower_case = ['a'-'z']
let upper_case = ['A'-'Z']
let letter = upper_case | lower_case
let letters = letter +

rule main = parse
 | digits '.' digits as f 
     { Float (float_of_string f) :: main lexbuf}
 | digits as n          { Int (int_of_string n) :: main lexbuf }
 | letters as s         { String s :: main lexbuf}
 | eof                  { [] }
 | _ { main lexbuf }

{
 let newlexbuf = (Lexing.from_channel stdin) in
 print_string "Ready to lex.\n";
 main newlexbuf
}