parser_utils.ml

   1 (* Simple wrapper tying together parser and lexer *)
   2
   3 module type Parser_type =
   4 sig
   5   type token
   6   type result
   7   val input : (Lexing.lexbuf -> token) -> Lexing.lexbuf -> result
   8   val rule : Lexing.lexbuf -> token
   9 end
  10
  11 exception Error of exn * (int * int * string)
  12
  13 module Make(T : Parser_type) =
  14 struct
  15   let parse_buf_exn lexbuf =
  16     try
  17       T.input T.rule lexbuf
  18     with exn ->
  19       begin
  20         let curr = lexbuf.Lexing.lex_curr_p in
  21         let line = curr.Lexing.pos_lnum in
  22         let cnum = curr.Lexing.pos_cnum - curr.Lexing.pos_bol in
  23         let tok = Lexing.lexeme lexbuf in
  24                                 raise (Error (exn,(line,cnum,tok)))
  25       end
  26
  27   let parse_buf lexbuf = try Some (parse_buf_exn lexbuf) with exn -> None
  28
  29   let parse_stdin () = parse_buf (Lexing.from_channel stdin)
  30   let parse_string str = (*Error.log "Parsing : %s" str; *)
  31                          parse_buf (Lexing.from_string str)
  32
  33   let parse_file filename =
  34     let contents = try Std.input_file filename with exn -> "" in
  35     parse_string contents
  36
  37 end