(***********************************************************************)
(*                                                                     *)
(*                           Objective Caml                            *)
(*                                                                     *)
               , projet Cristal , INRIA Rocquencourt         
(*                                                                     *)
   Copyright 1996 Institut National de Recherche en Informatique et   
   en Automatique .   All rights reserved .   This file is distributed    
   under the terms of the GNU Library General Public License , with    
(*  the special exception on linking described in file ../LICENSE.     *)
(*                                                                     *)
(***********************************************************************)

  $ Id$

(* The run-time library for lexers generated by camllex *)

type position = {
  pos_fname : string;
  pos_lnum : int;
  pos_bol : int;
  pos_cnum : int;
}

let dummy_pos = {
  pos_fname = "";
  pos_lnum = 0;
  pos_bol = 0;
  pos_cnum = -1;
}

type lexbuf =
  { refill_buff : lexbuf -> unit;
    mutable lex_buffer : string;
    mutable lex_buffer_len : int;
    mutable lex_abs_pos : int;
    mutable lex_start_pos : int;
    mutable lex_curr_pos : int;
    mutable lex_last_pos : int;
    mutable lex_last_action : int;
    mutable lex_eof_reached : bool;
    mutable lex_mem : int array;
    mutable lex_start_p : position;
    mutable lex_curr_p : position;
  }

type lex_tables =
  { lex_base: string;
    lex_backtrk: string;
    lex_default: string;
    lex_trans: string;
    lex_check: string;
    lex_base_code : string;
    lex_backtrk_code : string;
    lex_default_code : string;
    lex_trans_code : string;
    lex_check_code : string;
    lex_code: string;}

external c_engine : lex_tables -> int -> lexbuf -> int = "caml_lex_engine"
external c_new_engine : lex_tables -> int -> lexbuf -> int
                      = "caml_new_lex_engine"

let engine tbl state buf =
  let result = c_engine tbl state buf in
  if result >= 0 then begin
    buf.lex_start_p <- buf.lex_curr_p;
    buf.lex_curr_p <- {buf.lex_curr_p
                       with pos_cnum = buf.lex_abs_pos + buf.lex_curr_pos};
  end;
  result
;;

let new_engine tbl state buf =
  let result = c_new_engine tbl state buf in
  if result >= 0 then begin
    buf.lex_start_p <- buf.lex_curr_p;
    buf.lex_curr_p <- {buf.lex_curr_p
                       with pos_cnum = buf.lex_abs_pos + buf.lex_curr_pos};
  end;
  result
;;

let lex_refill read_fun aux_buffer lexbuf =
  let read =
    read_fun aux_buffer (String.length aux_buffer) in
  let n =
    if read > 0
    then read
    else (lexbuf.lex_eof_reached <- true; 0) in
  Current state of the buffer : 
         < -------|---------------------|----------- > 
         |   junk |       valid data      |    junk     | 
         ^        ^                      ^            ^ 
         0     start_pos              buffer_end     String.length buffer 
  
        <-------|---------------------|----------->
        |  junk |      valid data     |   junk    |
        ^       ^                     ^           ^
        0    start_pos             buffer_end    String.length buffer
  *)
  if lexbuf.lex_buffer_len + n > String.length lexbuf.lex_buffer then begin
    (* There is not enough space at the end of the buffer *)
    if lexbuf.lex_buffer_len - lexbuf.lex_start_pos + n
       <= String.length lexbuf.lex_buffer
    then begin
      (* But there is enough space if we reclaim the junk at the beginning
         of the buffer *)
      String.blit lexbuf.lex_buffer lexbuf.lex_start_pos
                  lexbuf.lex_buffer 0
                  (lexbuf.lex_buffer_len - lexbuf.lex_start_pos)
    end else begin
  We must grow the buffer .   Doubling its size will provide enough 
          space since n < = String.length aux_buffer < = String.length buffer . 
          Watch out for string length overflow , though .
         space since n <= String.length aux_buffer <= String.length buffer.
         Watch out for string length overflow, though. *)
      let newlen =
        min (2 * String.length lexbuf.lex_buffer) Sys.max_string_length in
      if lexbuf.lex_buffer_len - lexbuf.lex_start_pos + n > newlen
      then failwith "Lexing.lex_refill: cannot grow buffer";
      let newbuf = String.create newlen in
      (* Copy the valid data to the beginning of the new buffer *)
      String.blit lexbuf.lex_buffer lexbuf.lex_start_pos
                  newbuf 0
                  (lexbuf.lex_buffer_len - lexbuf.lex_start_pos);
      lexbuf.lex_buffer <- newbuf
    end;
    (* Reallocation or not, we have shifted the data left by
       start_pos characters; update the positions *)
    let s = lexbuf.lex_start_pos in
    lexbuf.lex_abs_pos <- lexbuf.lex_abs_pos + s;
    lexbuf.lex_curr_pos <- lexbuf.lex_curr_pos - s;
    lexbuf.lex_start_pos <- 0;
    lexbuf.lex_last_pos <- lexbuf.lex_last_pos - s;
    lexbuf.lex_buffer_len <- lexbuf.lex_buffer_len - s ;
    let t = lexbuf.lex_mem in
    for i = 0 to Array.length t-1 do
      let v = t.(i) in
      if v >= 0 then
        t.(i) <- v-s
    done
  end;
  (* There is now enough space at the end of the buffer *)
  String.blit aux_buffer 0
              lexbuf.lex_buffer lexbuf.lex_buffer_len
              n;
  lexbuf.lex_buffer_len <- lexbuf.lex_buffer_len + n

let zero_pos = {
  pos_fname = "";
  pos_lnum = 1;
  pos_bol = 0;
  pos_cnum = 0;
};;

let from_function f =
  { refill_buff = lex_refill f (String.create 512);
    lex_buffer = String.create 1024;
    lex_buffer_len = 0;
    lex_abs_pos = 0;
    lex_start_pos = 0;
    lex_curr_pos = 0;
    lex_last_pos = 0;
    lex_last_action = 0;
    lex_mem = [||];
    lex_eof_reached = false;
    lex_start_p = zero_pos;
    lex_curr_p = zero_pos;
  }

let from_channel ic =
  from_function (fun buf n -> input ic buf 0 n)

let from_string s =
  { refill_buff = (fun lexbuf -> lexbuf.lex_eof_reached <- true);
    lex_buffer = s ^ "";
    lex_buffer_len = String.length s;
    lex_abs_pos = 0;
    lex_start_pos = 0;
    lex_curr_pos = 0;
    lex_last_pos = 0;
    lex_last_action = 0;
    lex_mem = [||];
    lex_eof_reached = true;
    lex_start_p = zero_pos;
    lex_curr_p = zero_pos;
  }

let lexeme lexbuf =
  let len = lexbuf.lex_curr_pos - lexbuf.lex_start_pos in
  let s = String.create len in
  String.unsafe_blit lexbuf.lex_buffer lexbuf.lex_start_pos s 0 len;
  s

let sub_lexeme lexbuf i1 i2 =
  let len = i2-i1 in
  let s = String.create len in
  String.unsafe_blit lexbuf.lex_buffer i1 s 0 len;
  s

let sub_lexeme_opt lexbuf i1 i2 =
  if i1 >= 0 then begin
    let len = i2-i1 in
    let s = String.create len in
    String.unsafe_blit lexbuf.lex_buffer i1 s 0 len;
    Some s
  end else begin
    None
  end

let sub_lexeme_char lexbuf i = lexbuf.lex_buffer.[i]

let sub_lexeme_char_opt lexbuf i =
  if i >= 0 then
    Some lexbuf.lex_buffer.[i]
  else
    None


let lexeme_char lexbuf i =
  String.get lexbuf.lex_buffer (lexbuf.lex_start_pos + i)

let lexeme_start lexbuf = lexbuf.lex_start_p.pos_cnum;;
let lexeme_end lexbuf = lexbuf.lex_curr_p.pos_cnum;;

let lexeme_start_p lexbuf = lexbuf.lex_start_p;;
let lexeme_end_p lexbuf = lexbuf.lex_curr_p;;

let new_line lexbuf =
  let lcp = lexbuf.lex_curr_p in
  lexbuf.lex_curr_p <- { lcp with
    pos_lnum = lcp.pos_lnum + 1;
    pos_bol = lcp.pos_cnum;
  }
;;


(* Discard data left in lexer buffer. *)

let flush_input lb =
  lb.lex_curr_pos <- 0;
  lb.lex_abs_pos <- 0;
  lb.lex_curr_p <- {lb.lex_curr_p with pos_cnum = 0};
  lb.lex_buffer_len <- 0;
;;

*********************************************************************
                                                                     
                           Objective Caml                            
                                                                     
                                                                     
  the special exception on linking described in file ../LICENSE.     
                                                                     
*********************************************************************
 The run-time library for lexers generated by camllex 
 There is not enough space at the end of the buffer 
 But there is enough space if we reclaim the junk at the beginning
         of the buffer 
 Copy the valid data to the beginning of the new buffer 
 Reallocation or not, we have shifted the data left by
       start_pos characters; update the positions 
 There is now enough space at the end of the buffer 
 Discard data left in lexer buffer. 
               , projet Cristal , INRIA Rocquencourt         
   Copyright 1996 Institut National de Recherche en Informatique et   
   en Automatique .   All rights reserved .   This file is distributed    
   under the terms of the GNU Library General Public License , with    

  $ Id$


type position = {
  pos_fname : string;
  pos_lnum : int;
  pos_bol : int;
  pos_cnum : int;
}

let dummy_pos = {
  pos_fname = "";
  pos_lnum = 0;
  pos_bol = 0;
  pos_cnum = -1;
}

type lexbuf =
  { refill_buff : lexbuf -> unit;
    mutable lex_buffer : string;
    mutable lex_buffer_len : int;
    mutable lex_abs_pos : int;
    mutable lex_start_pos : int;
    mutable lex_curr_pos : int;
    mutable lex_last_pos : int;
    mutable lex_last_action : int;
    mutable lex_eof_reached : bool;
    mutable lex_mem : int array;
    mutable lex_start_p : position;
    mutable lex_curr_p : position;
  }

type lex_tables =
  { lex_base: string;
    lex_backtrk: string;
    lex_default: string;
    lex_trans: string;
    lex_check: string;
    lex_base_code : string;
    lex_backtrk_code : string;
    lex_default_code : string;
    lex_trans_code : string;
    lex_check_code : string;
    lex_code: string;}

external c_engine : lex_tables -> int -> lexbuf -> int = "caml_lex_engine"
external c_new_engine : lex_tables -> int -> lexbuf -> int
                      = "caml_new_lex_engine"

let engine tbl state buf =
  let result = c_engine tbl state buf in
  if result >= 0 then begin
    buf.lex_start_p <- buf.lex_curr_p;
    buf.lex_curr_p <- {buf.lex_curr_p
                       with pos_cnum = buf.lex_abs_pos + buf.lex_curr_pos};
  end;
  result
;;

let new_engine tbl state buf =
  let result = c_new_engine tbl state buf in
  if result >= 0 then begin
    buf.lex_start_p <- buf.lex_curr_p;
    buf.lex_curr_p <- {buf.lex_curr_p
                       with pos_cnum = buf.lex_abs_pos + buf.lex_curr_pos};
  end;
  result
;;

let lex_refill read_fun aux_buffer lexbuf =
  let read =
    read_fun aux_buffer (String.length aux_buffer) in
  let n =
    if read > 0
    then read
    else (lexbuf.lex_eof_reached <- true; 0) in
  Current state of the buffer : 
         < -------|---------------------|----------- > 
         |   junk |       valid data      |    junk     | 
         ^        ^                      ^            ^ 
         0     start_pos              buffer_end     String.length buffer 
  
        <-------|---------------------|----------->
        |  junk |      valid data     |   junk    |
        ^       ^                     ^           ^
        0    start_pos             buffer_end    String.length buffer
  *)
  if lexbuf.lex_buffer_len + n > String.length lexbuf.lex_buffer then begin
    if lexbuf.lex_buffer_len - lexbuf.lex_start_pos + n
       <= String.length lexbuf.lex_buffer
    then begin
      String.blit lexbuf.lex_buffer lexbuf.lex_start_pos
                  lexbuf.lex_buffer 0
                  (lexbuf.lex_buffer_len - lexbuf.lex_start_pos)
    end else begin
  We must grow the buffer .   Doubling its size will provide enough 
          space since n < = String.length aux_buffer < = String.length buffer . 
          Watch out for string length overflow , though .
         space since n <= String.length aux_buffer <= String.length buffer.
         Watch out for string length overflow, though. *)
      let newlen =
        min (2 * String.length lexbuf.lex_buffer) Sys.max_string_length in
      if lexbuf.lex_buffer_len - lexbuf.lex_start_pos + n > newlen
      then failwith "Lexing.lex_refill: cannot grow buffer";
      let newbuf = String.create newlen in
      String.blit lexbuf.lex_buffer lexbuf.lex_start_pos
                  newbuf 0
                  (lexbuf.lex_buffer_len - lexbuf.lex_start_pos);
      lexbuf.lex_buffer <- newbuf
    end;
    let s = lexbuf.lex_start_pos in
    lexbuf.lex_abs_pos <- lexbuf.lex_abs_pos + s;
    lexbuf.lex_curr_pos <- lexbuf.lex_curr_pos - s;
    lexbuf.lex_start_pos <- 0;
    lexbuf.lex_last_pos <- lexbuf.lex_last_pos - s;
    lexbuf.lex_buffer_len <- lexbuf.lex_buffer_len - s ;
    let t = lexbuf.lex_mem in
    for i = 0 to Array.length t-1 do
      let v = t.(i) in
      if v >= 0 then
        t.(i) <- v-s
    done
  end;
  String.blit aux_buffer 0
              lexbuf.lex_buffer lexbuf.lex_buffer_len
              n;
  lexbuf.lex_buffer_len <- lexbuf.lex_buffer_len + n

let zero_pos = {
  pos_fname = "";
  pos_lnum = 1;
  pos_bol = 0;
  pos_cnum = 0;
};;

let from_function f =
  { refill_buff = lex_refill f (String.create 512);
    lex_buffer = String.create 1024;
    lex_buffer_len = 0;
    lex_abs_pos = 0;
    lex_start_pos = 0;
    lex_curr_pos = 0;
    lex_last_pos = 0;
    lex_last_action = 0;
    lex_mem = [||];
    lex_eof_reached = false;
    lex_start_p = zero_pos;
    lex_curr_p = zero_pos;
  }

let from_channel ic =
  from_function (fun buf n -> input ic buf 0 n)

let from_string s =
  { refill_buff = (fun lexbuf -> lexbuf.lex_eof_reached <- true);
    lex_buffer = s ^ "";
    lex_buffer_len = String.length s;
    lex_abs_pos = 0;
    lex_start_pos = 0;
    lex_curr_pos = 0;
    lex_last_pos = 0;
    lex_last_action = 0;
    lex_mem = [||];
    lex_eof_reached = true;
    lex_start_p = zero_pos;
    lex_curr_p = zero_pos;
  }

let lexeme lexbuf =
  let len = lexbuf.lex_curr_pos - lexbuf.lex_start_pos in
  let s = String.create len in
  String.unsafe_blit lexbuf.lex_buffer lexbuf.lex_start_pos s 0 len;
  s

let sub_lexeme lexbuf i1 i2 =
  let len = i2-i1 in
  let s = String.create len in
  String.unsafe_blit lexbuf.lex_buffer i1 s 0 len;
  s

let sub_lexeme_opt lexbuf i1 i2 =
  if i1 >= 0 then begin
    let len = i2-i1 in
    let s = String.create len in
    String.unsafe_blit lexbuf.lex_buffer i1 s 0 len;
    Some s
  end else begin
    None
  end

let sub_lexeme_char lexbuf i = lexbuf.lex_buffer.[i]

let sub_lexeme_char_opt lexbuf i =
  if i >= 0 then
    Some lexbuf.lex_buffer.[i]
  else
    None


let lexeme_char lexbuf i =
  String.get lexbuf.lex_buffer (lexbuf.lex_start_pos + i)

let lexeme_start lexbuf = lexbuf.lex_start_p.pos_cnum;;
let lexeme_end lexbuf = lexbuf.lex_curr_p.pos_cnum;;

let lexeme_start_p lexbuf = lexbuf.lex_start_p;;
let lexeme_end_p lexbuf = lexbuf.lex_curr_p;;

let new_line lexbuf =
  let lcp = lexbuf.lex_curr_p in
  lexbuf.lex_curr_p <- { lcp with
    pos_lnum = lcp.pos_lnum + 1;
    pos_bol = lcp.pos_cnum;
  }
;;



let flush_input lb =
  lb.lex_curr_pos <- 0;
  lb.lex_abs_pos <- 0;
  lb.lex_curr_p <- {lb.lex_curr_p with pos_cnum = 0};
  lb.lex_buffer_len <- 0;
;;
