gcc/m2/gm2-compiler/bnflex.def

   1 (* bnflex.def provides a simple lexical package for pg.
   2
   3 Copyright (C) 2001-2023 Free Software Foundation, Inc.
   4 Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.
   5
   6 This file is part of GNU Modula-2.
   7
   8 GNU Modula-2 is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GNU Modula-2 is distributed in the hope that it will be useful, but
  14 WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU Modula-2; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  *)
  21
  22 DEFINITION MODULE bnflex ;
  23
  24 (*
  25     Title      : bnflex
  26     Author     : Gaius Mulley
  27     System     : UNIX (gm2)
  28     Date       : Mon Sep 13 08:53:02 1999
  29     Last edit  : Mon Sep 13 08:53:02 1999
  30     Description: provides a simple lexical package for pg.
  31 *)
  32
  33 FROM NameKey IMPORT Name ;
  34 EXPORT QUALIFIED IsSym, SymIs, TokenType, GetCurrentTokenType, GetCurrentToken,
  35                  GetChar, PutChar, OpenSource, CloseSource,
  36                  SkipUntilWhite, SkipWhite, SkipUntilEoln, AdvanceToken, IsReserved, PushBackToken,
  37                  SetDebugging ;
  38
  39 TYPE
  40    TokenType = (identtok, literaltok, codetok, lbecomestok, rbecomestok, bartok, lsparatok, rsparatok,
  41                 lcparatok, rcparatok, lparatok, rparatok, errortok, tfunctok, symfunctok,
  42                 squotetok, dquotetok, moduletok, begintok, rulestok, endtok, lesstok, gretok,
  43                 tokentok, specialtok, firsttok, followtok, BNFtok, FNBtok, declarationtok,
  44                 epsilontok, eoftok) ;
  45
  46
  47 (*
  48    OpenSource - Attempts to open the source file, a.
  49                 The success of the operation is returned.
  50 *)
  51
  52 PROCEDURE OpenSource (a: ARRAY OF CHAR) : BOOLEAN ;
  53
  54
  55 (*
  56    CloseSource - Closes the current open file.
  57 *)
  58
  59 PROCEDURE CloseSource ;
  60
  61
  62 (*
  63    GetChar - returns the current character on the input stream.
  64 *)
  65
  66 PROCEDURE GetChar () : CHAR ;
  67
  68
  69 (*
  70    PutChar - pushes a character onto the push back stack, it also
  71              returns the character which has been pushed.
  72 *)
  73
  74 PROCEDURE PutChar (ch: CHAR) : CHAR ;
  75
  76
  77 (*
  78    SymIs - if t is equal to the current token the next token is read
  79            and true is returned, otherwise false is returned.
  80 *)
  81
  82 PROCEDURE SymIs (t: TokenType) : BOOLEAN ;
  83
  84
  85 (*
  86    IsSym - returns the result of the comparison between the current token
  87            type and t.
  88 *)
  89
  90 PROCEDURE IsSym (t: TokenType) : BOOLEAN ;
  91
  92
  93 (*
  94    GetCurrentTokenType - returns the type of current token.
  95 *)
  96
  97 PROCEDURE GetCurrentTokenType () : TokenType ;
  98
  99
 100 (*
 101    GetCurrentToken - returns the NameKey of the current token.
 102 *)
 103
 104 PROCEDURE GetCurrentToken () : Name ;
 105
 106
 107 (*
 108    SkipUntilWhite - skips all characters until white space is seen.
 109 *)
 110
 111 PROCEDURE SkipUntilWhite ;
 112
 113
 114 (*
 115    SkipWhite - skips all white space.
 116 *)
 117
 118 PROCEDURE SkipWhite ;
 119
 120
 121 (*
 122    SkipUntilEoln - skips until a lf is seen. It consumes the lf.
 123 *)
 124
 125 PROCEDURE SkipUntilEoln ;
 126
 127
 128 (*
 129    AdvanceToken - advances to the next token.
 130 *)
 131
 132 PROCEDURE AdvanceToken ;
 133
 134
 135 (*
 136    IsReserved - returns TRUE if the name is a reserved word.
 137 *)
 138
 139 PROCEDURE IsReserved (name: Name) : BOOLEAN ;
 140
 141
 142 (*
 143    PushBackToken - pushes a token back onto input.
 144 *)
 145
 146 PROCEDURE PushBackToken (t: Name) ;
 147
 148
 149 (*
 150    SetDebugging - sets the debugging flag.
 151 *)
 152
 153 PROCEDURE SetDebugging (flag: BOOLEAN) ;
 154
 155
 156 END bnflex.