ocaml/lex/main.ml

49 lines
1.3 KiB
OCaml

(* The lexer generator. Command-line parsing. *)
open Syntax
open Lexgen
open Output
let main () =
if Array.length Sys.argv != 2 then begin
prerr_endline "Usage: camllex <input file>";
exit 2
end;
let source_name = Sys.argv.(1) in
let dest_name =
if Filename.check_suffix source_name ".mll" then
Filename.chop_suffix source_name ".mll" ^ ".ml"
else
source_name ^ ".ml" in
ic := open_in_bin source_name;
oc := open_out dest_name;
let lexbuf =
Lexing.from_channel !ic in
let (Lexdef(header,_) as def) =
try
Parser.lexer_definition Lexer.main lexbuf
with exn ->
close_out !oc;
Sys.remove dest_name;
begin match exn with
Parsing.Parse_error ->
prerr_string "Syntax error around char ";
prerr_int (Lexing.lexeme_start lexbuf);
prerr_endline "."
| Lexer.Lexical_error s ->
prerr_string "Lexical error around char ";
prerr_int (Lexing.lexeme_start lexbuf);
prerr_string ": ";
prerr_string s;
prerr_endline "."
| _ -> raise exn
end;
exit 2 in
let ((init, states, acts) as dfa) = make_dfa def in
output_lexdef header dfa;
close_in !ic;
close_out !oc
let _ = Printexc.catch main (); exit 0