pga/lexer.mll

{
open Lexing
open Parser

exception Syntax_error of string

let next_line lexbuf =
  let pos = lexbuf.lex_curr_p in
  lexbuf.lex_curr_p <- {
    pos with pos_bol = lexbuf.lex_curr_pos;
             pos_lnum = pos.pos_lnum + 1
  }
}

rule token = parse
  | ';'       { SEMICOL }
  | '!'       { EXCLAM }
  | '+'       { PLUS }
  | '-'       { MINUS }
  | '#'       { HASH }
  | '*'       { OMEGA }
  | '('       { LPAREN }
  | ')'       { RPAREN }
(*
  | '{'       { LBRACE }
  | '}'       { RBRACE }
*)

  | ['0'-'9']+ as i { NUMBER (int_of_string i) }
  | ['A'-'Z'] as c  { UPPER c }
  | ['a'-'z'] as c  { LOWER c }

  | '\r' | '\n' | "\r\n"  { next_line lexbuf; token lexbuf }
  | [' ''\t']+            { token lexbuf }
  | eof | '\000'          { EOF }

  | _ as chr { raise (Syntax_error ("unexpected '" ^ Char.escaped chr ^ "'")) }