(* mcLexBuf.def provides a buffer for the all the tokens created by m2.lex.

Copyright (C) 2015-2023 Free Software Foundation, Inc.
Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.

This file is part of GNU Modula-2.

GNU Modula-2 is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.

GNU Modula-2 is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Modula-2; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  *)

DEFINITION MODULE mcLexBuf ;


FROM SYSTEM IMPORT ADDRESS ;
FROM mcReserved IMPORT toktype ;
FROM DynamicStrings IMPORT String ;
FROM mcComment IMPORT commentDesc ;


VAR
   currenttoken  : toktype ;
   currentstring : ADDRESS ;
   currentcolumn : CARDINAL ;
   currentinteger: INTEGER ;
   lastcomment,
   currentcomment: commentDesc ;


(*
   getProcedureComment - returns the procedure comment if it exists,
                         or NIL otherwise.
*)

PROCEDURE getProcedureComment () : commentDesc ;


(*
   getBodyComment - returns the body comment if it exists,
                    or NIL otherwise.
*)

PROCEDURE getBodyComment () : commentDesc ;


(*
   getAfterComment - returns the after comment if it exists,
                     or NIL otherwise.
*)

PROCEDURE getAfterComment () : commentDesc ;


(*
   openSource - Attempts to open the source file, s.
                The success of the operation is returned.
*)

PROCEDURE openSource (s: String) : BOOLEAN ;


(*
   closeSource - closes the current open file.
*)

PROCEDURE closeSource ;


(*
   reInitialize - re-initialize the all the data structures.
*)

PROCEDURE reInitialize ;


(*
   resetForNewPass - reset the buffer pointers to the beginning ready for
                     a new pass
*)

PROCEDURE resetForNewPass ;


(*
   getToken - gets the next token into currenttoken.
*)

PROCEDURE getToken ;


(*
   insertToken - inserts a symbol, token, infront of the current token
                 ready for the next pass.
*)

PROCEDURE insertToken (token: toktype) ;


(*
   insertTokenAndRewind - inserts a symbol, token, infront of the current token
                          and then moves the token stream back onto the inserted token.
*)

PROCEDURE insertTokenAndRewind (token: toktype) ;


(*
   getPreviousTokenLineNo - returns the line number of the previous token.
*)

PROCEDURE getPreviousTokenLineNo () : CARDINAL ;


(*
   getLineNo - returns the current line number where the symbol occurs in
               the source file.
*)

PROCEDURE getLineNo () : CARDINAL ;


(*
   getTokenNo - returns the current token number.
*)

PROCEDURE getTokenNo () : CARDINAL ;


(*
   tokenToLineNo - returns the line number of the current file for the
                   TokenNo. The depth refers to the include depth.
                   A depth of 0 is the current file, depth of 1 is the file
                   which included the current file. Zero is returned if the
                   depth exceeds the file nesting level.
*)

PROCEDURE tokenToLineNo (tokenNo: CARDINAL; depth: CARDINAL) : CARDINAL ;


(*
   getColumnNo - returns the current column where the symbol occurs in
                 the source file.
*)

PROCEDURE getColumnNo () : CARDINAL ;


(*
   tokenToColumnNo - returns the column number of the current file for the
                     TokenNo. The depth refers to the include depth.
                     A depth of 0 is the current file, depth of 1 is the file
                     which included the current file. Zero is returned if the
                     depth exceeds the file nesting level.
*)

PROCEDURE tokenToColumnNo (tokenNo: CARDINAL; depth: CARDINAL) : CARDINAL ;


(*
   findFileNameFromToken - returns the complete FileName for the appropriate
                           source file yields the token number, TokenNo.
                           The, Depth, indicates the include level: 0..n
                           Level 0 is the current. NIL is returned if n+1
                           is requested.
*)

PROCEDURE findFileNameFromToken (tokenNo: CARDINAL; depth: CARDINAL) : String ;


(*
   getFileName - returns a String defining the current file.
*)

PROCEDURE getFileName () : String ;


(* ***********************************************************************
 *
 * These functions allow m2.lex to deliver tokens into the buffer
 *
 ************************************************************************* *)

(*
   addTok - adds a token to the buffer.
*)

PROCEDURE addTok (t: toktype) ;


(*
   addTokCharStar - adds a token to the buffer and an additional string, s.
                    A copy of string, s, is made.
*)

PROCEDURE addTokCharStar (t: toktype; s: ADDRESS) ;


(*
   addTokInteger - adds a token and an integer to the buffer.
*)

PROCEDURE addTokInteger (t: toktype; i: INTEGER) ;


(*
   addTokComment - adds a token to the buffer and a comment descriptor, com.
*)

PROCEDURE addTokComment (t: toktype; com: commentDesc) ;


(*
   setFile - sets the current filename to, filename.
*)

PROCEDURE setFile (filename: ADDRESS) ;


(*
   pushFile - indicates that, filename, has just been included.
*)

PROCEDURE pushFile (filename: ADDRESS) ;


(*
   popFile - indicates that we are returning to, filename, having finished
             an include.
*)

PROCEDURE popFile (filename: ADDRESS) ;


END mcLexBuf.