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(**************************************************************************)
(* *)
(* Menhir *)
(* *)
(* François Pottier, INRIA Rocquencourt *)
(* Yann Régis-Gianas, PPS, Université Paris Diderot *)
(* *)
(* Copyright 2005-2008 Institut National de Recherche en Informatique *)
(* et en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the Q Public License version 1.0, with the change *)
(* described in file LICENSE. *)
(* *)
(**************************************************************************)
{
open Tokens
exception Error of string
}
(* This rule looks for a single line, terminated with '\n' or eof.
It returns a pair of an optional string (the line that was found)
and a Boolean flag (false if eof was reached). *)
rule line = parse
| ([^'\n']* '\n') as line
(* Normal case: one line, no eof. *)
{ Some line, true }
| eof
(* Normal case: no data, eof. *)
{ None, false }
| ([^'\n']+ as line) eof
(* Special case: some data but missing '\n', then eof.
Consider this as the last line, and add the missing '\n'. *)
{ Some (line ^ "\n"), false }
(* This rule analyzes a single line and turns it into a stream of
tokens. *)
and token = parse
| [' ' '\t']
{ token lexbuf }
| '\n'
{ EOL }
| ['0'-'9']+ as i
{ INT (int_of_string i) }
| '+'
{ PLUS }
| '-'
{ MINUS }
| '*'
{ TIMES }
| '/'
{ DIV }
| '('
{ LPAREN }
| ')'
{ RPAREN }
| _
{ raise (Error (Printf.sprintf "At offset %d: unexpected character.\n" (Lexing.lexeme_start lexbuf))) }
|