515 lines
15 KiB
OCaml
515 lines
15 KiB
OCaml
(***********************************************************************)
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(* *)
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(* OCaml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1996 Institut National de Recherche en Informatique et *)
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(* en Automatique. All rights reserved. This file is distributed *)
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(* under the terms of the Q Public License version 1.0. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* The lexer definition *)
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{
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open Lexing
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open Misc
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open Parser
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type error =
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| Illegal_character of char
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| Illegal_escape of string
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| Unterminated_comment
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| Unterminated_string
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| Unterminated_string_in_comment
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| Keyword_as_label of string
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| Literal_overflow of string
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;;
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exception Error of error * Location.t;;
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(* The table of keywords *)
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let keyword_table =
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create_hashtable 149 [
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"and", AND;
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"as", AS;
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"assert", ASSERT;
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"begin", BEGIN;
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"class", CLASS;
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"constraint", CONSTRAINT;
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"do", DO;
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"done", DONE;
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"downto", DOWNTO;
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"else", ELSE;
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"end", END;
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"exception", EXCEPTION;
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"external", EXTERNAL;
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"false", FALSE;
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"for", FOR;
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"fun", FUN;
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"function", FUNCTION;
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"functor", FUNCTOR;
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"if", IF;
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"in", IN;
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"include", INCLUDE;
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"inherit", INHERIT;
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"initializer", INITIALIZER;
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"lazy", LAZY;
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"let", LET;
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"match", MATCH;
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"method", METHOD;
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"module", MODULE;
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"mutable", MUTABLE;
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"new", NEW;
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"object", OBJECT;
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"of", OF;
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"open", OPEN;
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"or", OR;
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(* "parser", PARSER; *)
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"private", PRIVATE;
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"rec", REC;
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"sig", SIG;
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"struct", STRUCT;
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"then", THEN;
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"to", TO;
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"true", TRUE;
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"try", TRY;
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"type", TYPE;
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"val", VAL;
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"virtual", VIRTUAL;
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"when", WHEN;
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"while", WHILE;
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"with", WITH;
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"mod", INFIXOP3("mod");
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"land", INFIXOP3("land");
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"lor", INFIXOP3("lor");
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"lxor", INFIXOP3("lxor");
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"lsl", INFIXOP4("lsl");
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"lsr", INFIXOP4("lsr");
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"asr", INFIXOP4("asr")
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]
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(* To buffer string literals *)
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let initial_string_buffer = String.create 256
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let string_buff = ref initial_string_buffer
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let string_index = ref 0
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let reset_string_buffer () =
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string_buff := initial_string_buffer;
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string_index := 0
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let store_string_char c =
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if !string_index >= String.length (!string_buff) then begin
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let new_buff = String.create (String.length (!string_buff) * 2) in
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String.blit (!string_buff) 0 new_buff 0 (String.length (!string_buff));
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string_buff := new_buff
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end;
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String.unsafe_set (!string_buff) (!string_index) c;
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incr string_index
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let get_stored_string () =
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let s = String.sub (!string_buff) 0 (!string_index) in
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string_buff := initial_string_buffer;
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s
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(* To store the position of the beginning of a string and comment *)
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let string_start_loc = ref Location.none;;
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let comment_start_loc = ref [];;
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let in_comment () = !comment_start_loc <> [];;
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(* To translate escape sequences *)
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let char_for_backslash = function
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| 'n' -> '\010'
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| 'r' -> '\013'
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| 'b' -> '\008'
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| 't' -> '\009'
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| c -> c
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let char_for_decimal_code lexbuf i =
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let c = 100 * (Char.code(Lexing.lexeme_char lexbuf i) - 48) +
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10 * (Char.code(Lexing.lexeme_char lexbuf (i+1)) - 48) +
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(Char.code(Lexing.lexeme_char lexbuf (i+2)) - 48) in
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if (c < 0 || c > 255) then
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if in_comment ()
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then 'x'
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else raise (Error(Illegal_escape (Lexing.lexeme lexbuf),
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Location.curr lexbuf))
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else Char.chr c
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let char_for_hexadecimal_code lexbuf i =
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let d1 = Char.code (Lexing.lexeme_char lexbuf i) in
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let val1 = if d1 >= 97 then d1 - 87
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else if d1 >= 65 then d1 - 55
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else d1 - 48
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in
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let d2 = Char.code (Lexing.lexeme_char lexbuf (i+1)) in
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let val2 = if d2 >= 97 then d2 - 87
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else if d2 >= 65 then d2 - 55
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else d2 - 48
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in
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Char.chr (val1 * 16 + val2)
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(* To convert integer literals, allowing max_int + 1 (PR#4210) *)
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let cvt_int_literal s =
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- int_of_string ("-" ^ s)
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let cvt_int32_literal s =
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Int32.neg (Int32.of_string ("-" ^ String.sub s 0 (String.length s - 1)))
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let cvt_int64_literal s =
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Int64.neg (Int64.of_string ("-" ^ String.sub s 0 (String.length s - 1)))
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let cvt_nativeint_literal s =
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Nativeint.neg (Nativeint.of_string ("-" ^ String.sub s 0 (String.length s - 1)))
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(* Remove underscores from float literals *)
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let remove_underscores s =
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let l = String.length s in
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let rec remove src dst =
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if src >= l then
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if dst >= l then s else String.sub s 0 dst
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else
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match s.[src] with
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'_' -> remove (src + 1) dst
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| c -> s.[dst] <- c; remove (src + 1) (dst + 1)
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in remove 0 0
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(* Update the current location with file name and line number. *)
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let update_loc lexbuf file line absolute chars =
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let pos = lexbuf.lex_curr_p in
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let new_file = match file with
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| None -> pos.pos_fname
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| Some s -> s
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in
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lexbuf.lex_curr_p <- { pos with
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pos_fname = new_file;
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pos_lnum = if absolute then line else pos.pos_lnum + line;
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pos_bol = pos.pos_cnum - chars;
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}
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;;
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(* Error report *)
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open Format
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let report_error ppf = function
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| Illegal_character c ->
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fprintf ppf "Illegal character (%s)" (Char.escaped c)
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| Illegal_escape s ->
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fprintf ppf "Illegal backslash escape in string or character (%s)" s
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| Unterminated_comment ->
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fprintf ppf "Comment not terminated"
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| Unterminated_string ->
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fprintf ppf "String literal not terminated"
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| Unterminated_string_in_comment ->
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fprintf ppf "This comment contains an unterminated string literal"
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| Keyword_as_label kwd ->
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fprintf ppf "`%s' is a keyword, it cannot be used as label name" kwd
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| Literal_overflow ty ->
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fprintf ppf "Integer literal exceeds the range of representable integers of type %s" ty
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;;
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}
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let newline = ('\010' | "\013\010" )
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let blank = [' ' '\009' '\012']
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let lowercase = ['a'-'z' '\223'-'\246' '\248'-'\255' '_']
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let uppercase = ['A'-'Z' '\192'-'\214' '\216'-'\222']
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let identchar =
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['A'-'Z' 'a'-'z' '_' '\192'-'\214' '\216'-'\246' '\248'-'\255' '\'' '0'-'9']
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let symbolchar =
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['!' '$' '%' '&' '*' '+' '-' '.' '/' ':' '<' '=' '>' '?' '@' '^' '|' '~']
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let decimal_literal =
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['0'-'9'] ['0'-'9' '_']*
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let hex_literal =
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'0' ['x' 'X'] ['0'-'9' 'A'-'F' 'a'-'f']['0'-'9' 'A'-'F' 'a'-'f' '_']*
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let oct_literal =
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'0' ['o' 'O'] ['0'-'7'] ['0'-'7' '_']*
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let bin_literal =
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'0' ['b' 'B'] ['0'-'1'] ['0'-'1' '_']*
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let int_literal =
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decimal_literal | hex_literal | oct_literal | bin_literal
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let float_literal =
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['0'-'9'] ['0'-'9' '_']*
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('.' ['0'-'9' '_']* )?
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(['e' 'E'] ['+' '-']? ['0'-'9'] ['0'-'9' '_']*)?
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rule token = parse
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| newline
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{ update_loc lexbuf None 1 false 0;
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token lexbuf
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}
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| blank +
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{ token lexbuf }
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| "_"
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{ UNDERSCORE }
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| "~"
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{ TILDE }
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| "~" lowercase identchar * ':'
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{ let s = Lexing.lexeme lexbuf in
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let name = String.sub s 1 (String.length s - 2) in
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if Hashtbl.mem keyword_table name then
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raise (Error(Keyword_as_label name, Location.curr lexbuf));
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LABEL name }
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| "?" { QUESTION }
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| "??" { QUESTIONQUESTION }
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| "?" lowercase identchar * ':'
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{ let s = Lexing.lexeme lexbuf in
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let name = String.sub s 1 (String.length s - 2) in
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if Hashtbl.mem keyword_table name then
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raise (Error(Keyword_as_label name, Location.curr lexbuf));
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OPTLABEL name }
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| lowercase identchar *
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{ let s = Lexing.lexeme lexbuf in
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try
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Hashtbl.find keyword_table s
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with Not_found ->
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LIDENT s }
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| uppercase identchar *
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{ UIDENT(Lexing.lexeme lexbuf) } (* No capitalized keywords *)
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| int_literal
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{ try
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INT (cvt_int_literal (Lexing.lexeme lexbuf))
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with Failure _ ->
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raise (Error(Literal_overflow "int", Location.curr lexbuf))
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}
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| float_literal
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{ FLOAT (remove_underscores(Lexing.lexeme lexbuf)) }
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| int_literal "l"
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{ try
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INT32 (cvt_int32_literal (Lexing.lexeme lexbuf))
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with Failure _ ->
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raise (Error(Literal_overflow "int32", Location.curr lexbuf)) }
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| int_literal "L"
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{ try
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INT64 (cvt_int64_literal (Lexing.lexeme lexbuf))
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with Failure _ ->
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raise (Error(Literal_overflow "int64", Location.curr lexbuf)) }
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| int_literal "n"
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{ try
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NATIVEINT (cvt_nativeint_literal (Lexing.lexeme lexbuf))
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with Failure _ ->
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raise (Error(Literal_overflow "nativeint", Location.curr lexbuf)) }
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| "\""
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{ reset_string_buffer();
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let string_start = lexbuf.lex_start_p in
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string_start_loc := Location.curr lexbuf;
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string lexbuf;
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lexbuf.lex_start_p <- string_start;
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STRING (get_stored_string()) }
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| "'" newline "'"
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{ update_loc lexbuf None 1 false 1;
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CHAR (Lexing.lexeme_char lexbuf 1) }
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| "'" [^ '\\' '\'' '\010' '\013'] "'"
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{ CHAR(Lexing.lexeme_char lexbuf 1) }
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| "'\\" ['\\' '\'' '"' 'n' 't' 'b' 'r' ' '] "'"
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{ CHAR(char_for_backslash (Lexing.lexeme_char lexbuf 2)) }
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| "'\\" ['0'-'9'] ['0'-'9'] ['0'-'9'] "'"
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{ CHAR(char_for_decimal_code lexbuf 2) }
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| "'\\" 'x' ['0'-'9' 'a'-'f' 'A'-'F'] ['0'-'9' 'a'-'f' 'A'-'F'] "'"
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{ CHAR(char_for_hexadecimal_code lexbuf 3) }
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| "'\\" _
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{ let l = Lexing.lexeme lexbuf in
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let esc = String.sub l 1 (String.length l - 1) in
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raise (Error(Illegal_escape esc, Location.curr lexbuf))
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}
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| "(*"
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{ comment_start_loc := [Location.curr lexbuf];
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comment lexbuf;
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token lexbuf }
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| "(*)"
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{ let loc = Location.curr lexbuf in
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Location.prerr_warning loc Warnings.Comment_start;
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comment_start_loc := [Location.curr lexbuf];
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comment lexbuf;
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token lexbuf
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}
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| "*)"
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{ let loc = Location.curr lexbuf in
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Location.prerr_warning loc Warnings.Comment_not_end;
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lexbuf.Lexing.lex_curr_pos <- lexbuf.Lexing.lex_curr_pos - 1;
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let curpos = lexbuf.lex_curr_p in
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lexbuf.lex_curr_p <- { curpos with pos_cnum = curpos.pos_cnum - 1 };
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STAR
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}
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| "#" [' ' '\t']* (['0'-'9']+ as num) [' ' '\t']*
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("\"" ([^ '\010' '\013' '"' ] * as name) "\"")?
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[^ '\010' '\013'] * newline
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{ update_loc lexbuf name (int_of_string num) true 0;
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token lexbuf
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}
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| "#" { SHARP }
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| "&" { AMPERSAND }
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| "&&" { AMPERAMPER }
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| "`" { BACKQUOTE }
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| "'" { QUOTE }
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| "(" { LPAREN }
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| ")" { RPAREN }
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| "*" { STAR }
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| "," { COMMA }
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| "->" { MINUSGREATER }
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| "." { DOT }
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| ".." { DOTDOT }
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| ":" { COLON }
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| "::" { COLONCOLON }
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| ":=" { COLONEQUAL }
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| ":>" { COLONGREATER }
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| ";" { SEMI }
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| ";;" { SEMISEMI }
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| "<" { LESS }
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| "<-" { LESSMINUS }
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| "=" { EQUAL }
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| "[" { LBRACKET }
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| "[|" { LBRACKETBAR }
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| "[<" { LBRACKETLESS }
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| "[>" { LBRACKETGREATER }
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| "]" { RBRACKET }
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| "{" { LBRACE }
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| "{<" { LBRACELESS }
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| "|" { BAR }
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| "||" { BARBAR }
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| "|]" { BARRBRACKET }
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| ">" { GREATER }
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| ">]" { GREATERRBRACKET }
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| "}" { RBRACE }
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| ">}" { GREATERRBRACE }
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| "!" { BANG }
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| "!=" { INFIXOP0 "!=" }
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| "+" { PLUS }
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| "+." { PLUSDOT }
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| "-" { MINUS }
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| "-." { MINUSDOT }
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| "!" symbolchar +
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{ PREFIXOP(Lexing.lexeme lexbuf) }
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| ['~' '?'] symbolchar +
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{ PREFIXOP(Lexing.lexeme lexbuf) }
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| ['=' '<' '>' '|' '&' '$'] symbolchar *
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{ INFIXOP0(Lexing.lexeme lexbuf) }
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| ['@' '^'] symbolchar *
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{ INFIXOP1(Lexing.lexeme lexbuf) }
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| ['+' '-'] symbolchar *
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{ INFIXOP2(Lexing.lexeme lexbuf) }
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| "**" symbolchar *
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{ INFIXOP4(Lexing.lexeme lexbuf) }
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| ['*' '/' '%'] symbolchar *
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{ INFIXOP3(Lexing.lexeme lexbuf) }
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| eof { EOF }
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| _
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{ raise (Error(Illegal_character (Lexing.lexeme_char lexbuf 0),
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Location.curr lexbuf))
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}
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and comment = parse
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"(*"
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{ comment_start_loc := (Location.curr lexbuf) :: !comment_start_loc;
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comment lexbuf;
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}
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| "*)"
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{ match !comment_start_loc with
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| [] -> assert false
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| [_] -> comment_start_loc := [];
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| _ :: l -> comment_start_loc := l;
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comment lexbuf;
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}
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| "\""
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{ reset_string_buffer();
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string_start_loc := Location.curr lexbuf;
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begin try string lexbuf
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with Error (Unterminated_string, _) ->
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match !comment_start_loc with
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| [] -> assert false
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| loc :: _ -> comment_start_loc := [];
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raise (Error (Unterminated_string_in_comment, loc))
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end;
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reset_string_buffer ();
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comment lexbuf }
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| "''"
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{ comment lexbuf }
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| "'" newline "'"
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{ update_loc lexbuf None 1 false 1;
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comment lexbuf
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}
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| "'" [^ '\\' '\'' '\010' '\013' ] "'"
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{ comment lexbuf }
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| "'\\" ['\\' '"' '\'' 'n' 't' 'b' 'r' ' '] "'"
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{ comment lexbuf }
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| "'\\" ['0'-'9'] ['0'-'9'] ['0'-'9'] "'"
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{ comment lexbuf }
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| "'\\" 'x' ['0'-'9' 'a'-'f' 'A'-'F'] ['0'-'9' 'a'-'f' 'A'-'F'] "'"
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{ comment lexbuf }
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| eof
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{ match !comment_start_loc with
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| [] -> assert false
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| loc :: _ -> comment_start_loc := [];
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raise (Error (Unterminated_comment, loc))
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}
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| newline
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{ update_loc lexbuf None 1 false 0;
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comment lexbuf
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}
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| _
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{ comment lexbuf }
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and string = parse
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'"'
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{ () }
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| '\\' newline ([' ' '\t'] * as space)
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{ update_loc lexbuf None 1 false (String.length space);
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string lexbuf
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}
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| '\\' ['\\' '\'' '"' 'n' 't' 'b' 'r' ' ']
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{ store_string_char(char_for_backslash(Lexing.lexeme_char lexbuf 1));
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string lexbuf }
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| '\\' ['0'-'9'] ['0'-'9'] ['0'-'9']
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{ store_string_char(char_for_decimal_code lexbuf 1);
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string lexbuf }
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| '\\' 'x' ['0'-'9' 'a'-'f' 'A'-'F'] ['0'-'9' 'a'-'f' 'A'-'F']
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{ store_string_char(char_for_hexadecimal_code lexbuf 2);
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string lexbuf }
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| '\\' _
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{ if in_comment ()
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then string lexbuf
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else begin
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(* Should be an error, but we are very lax.
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raise (Error (Illegal_escape (Lexing.lexeme lexbuf),
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Location.curr lexbuf))
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*)
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let loc = Location.curr lexbuf in
|
|
Location.prerr_warning loc Warnings.Illegal_backslash;
|
|
store_string_char (Lexing.lexeme_char lexbuf 0);
|
|
store_string_char (Lexing.lexeme_char lexbuf 1);
|
|
string lexbuf
|
|
end
|
|
}
|
|
| newline
|
|
{ if not (in_comment ()) then
|
|
Location.prerr_warning (Location.curr lexbuf) Warnings.Eol_in_string;
|
|
update_loc lexbuf None 1 false 0;
|
|
let s = Lexing.lexeme lexbuf in
|
|
for i = 0 to String.length s - 1 do
|
|
store_string_char s.[i];
|
|
done;
|
|
string lexbuf
|
|
}
|
|
| eof
|
|
{ raise (Error (Unterminated_string, !string_start_loc)) }
|
|
| _
|
|
{ store_string_char(Lexing.lexeme_char lexbuf 0);
|
|
string lexbuf }
|
|
|
|
and skip_sharp_bang = parse
|
|
| "#!" [^ '\n']* '\n' [^ '\n']* "\n!#\n"
|
|
{ update_loc lexbuf None 3 false 0 }
|
|
| "#!" [^ '\n']* '\n'
|
|
{ update_loc lexbuf None 1 false 0 }
|
|
| "" { () }
|