(* CLexBuf.def provides a lexical buffer for clex.

Copyright (C) 2003-2023 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 CLexBuf ;

(*
    Title      : CLexBuf
    Author     : Gaius Mulley
    System     : GNU Modula-2
    Date       : Thu Jan 23 12:32:36 2003
    Revision   : $Version$
    Description: provides a lexical buffer for clex.
*)

FROM SYSTEM IMPORT ADDRESS ;
FROM DynamicStrings IMPORT String ;
FROM NameKey IMPORT Name ;
EXPORT QUALIFIED toktype,
                 IsMacroDefined, NoArgs, DefineMacro, UnDefineMacro,
                 OpenSource, CloseSource, ReInitialize, GetToken, InsertToken,
                 InsertTokenAndRewind, GetLineNo,
                 GetTokenNo, TokenToLineNo, FindFileNameFromToken, GetFileName,
                 ResetForNewPass,
                 currenttoken, currentstring, currentinteger,
                 EnableMacroSubstitutions,
                 AddTok, AddTokCharStar, AddTokInteger,
                 SetFile, PushFile, PopFile, FlushTokens ;

TYPE
   toktype = (eoftok, startok, arrowtok, structtok, lsbratok, rsbratok,
              lcbratok, rcbratok, lparatok, rparatok, semicolontok,
              longtok, inttok, chartok, enumtok, typedeftok,
              floattok, doubletok, unsignedtok, consttok,
              periodperiodperiodtok,
              integertok, hexintegertok, octintegertok,
              identtok, realtok, conststringtok, constchartok, codetok,
              starthashtok, endhashtok, definetok, undeftok, iftok, elsetok,
              endiftok, ifdeftok, ifndeftok, includetok,
              nottok, commatok,
              periodtok,
              gretok, lesstok, ortok, andtok, bartok, ambersandtok,
              shiftlefttok, shiftrighttok, divtok, modtok,
              sizeoftok, definedtok, hattok, equaltok, notequaltok,
              greequaltok, lessequaltok, plustok, minustok, tildetok,
              externtok, statictok, autotok, registertok,
              voidtok, shorttok, signedtok, uniontok, colontok, becomestok,
              volatiletok, typetok) ;

VAR
   currenttoken  : toktype ;
   currentstring : ADDRESS ;
   currentinteger: INTEGER ;


(*
   EnableMacroSubstitutions -
*)

PROCEDURE EnableMacroSubstitutions (b: BOOLEAN) ;


(*
   IsMacroDefined - returns TRUE if macro, n, was defined.
*)

PROCEDURE IsMacroDefined (n: Name) : BOOLEAN ;


(*
   NoArgs - returns the number of arguments for macro, n.
            -1 if the macro does not exist
*)

PROCEDURE NoArgs (n: Name) : INTEGER ;


(*
   DefineMacro - defines macro, n, as defined to start at token, t.
*)

PROCEDURE DefineMacro (n: Name; t: CARDINAL) ;


(*
   UnDefineMacro -
*)

PROCEDURE UnDefineMacro (n: Name) ;


(*
   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) ;


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

PROCEDURE GetLineNo () : CARDINAL ;


(*
   GetTokenNo - returns the number of tokens read from
                the source file by the lexical analaysis.
*)

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 ;


(*
   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 - assigns, a, to the current file name.
*)

PROCEDURE GetFileName () : String ;


(* ***********************************************************************
 *
 * These functions allow c.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) ;


(*
   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) ;


(*
   FlushTokens - removes the last token.
*)

PROCEDURE FlushTokens ;


END CLexBuf.