{
open InfSatParser
exception LexError of string
let line_no = ref 1
let end_of_previousline = ref 0
}

let space = [' ' '\t' '\r']
let newline = ['\n']
let digit = ['0'-'9']
let lower = ['a'-'z']
let upper = ['A'-'Z']

rule token = parse
| space+
  { token lexbuf }
| newline
  { end_of_previousline := (Lexing.lexeme_end lexbuf);
    line_no := !line_no+1;
    token lexbuf}
| "(*"
  { comment lexbuf;
    token lexbuf }
| "Grammar."
  { BEGING }
| "End."
  { END }
| "Terminals."
  { BEGINT }
| "fun"
  { FUN }
| "->"
  { ARROW }
| "("
  { LPAR }
| ")"
  { RPAR }
| "$"
  { COUNTED }
| "+"
  { EXISTENTIAL }
| "*"
  { UNIVERSAL }
| "."
  { PERIOD }
| digit digit* 
  { let s = Lexing.lexeme lexbuf in
    INT(int_of_string s)}
| lower (digit|lower|upper|'_')*
  { let s = Lexing.lexeme lexbuf in
    NAME(s)}
| upper (digit|lower|upper|'_')*
  { let s = Lexing.lexeme lexbuf in
    NONTERM(s)}
| eof
  { EOF }
| _
  { Format.eprintf "unknown token %s in line %d, column %d-%d @."
      (Lexing.lexeme lexbuf)
      (!line_no)
      ((Lexing.lexeme_start lexbuf)- (!end_of_previousline))
      ((Lexing.lexeme_end lexbuf)-(!end_of_previousline));
    failwith "lex error" }
and comment = parse
| "*)"
  { () }
| "(*"
  { comment lexbuf;
    comment lexbuf }
| eof
  { print_string "Lex error: unterminated comment\n";
    failwith "unterminated comment" }
| _
  { comment lexbuf }