1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
(* bnflex.def provides a simple lexical package for pg.
Copyright (C) 2001-2024 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 bnflex ;
(*
Title : bnflex
Author : Gaius Mulley
System : UNIX (gm2)
Date : Mon Sep 13 08:53:02 1999
Last edit : Mon Sep 13 08:53:02 1999
Description: provides a simple lexical package for pg.
*)
FROM NameKey IMPORT Name ;
EXPORT QUALIFIED IsSym, SymIs, TokenType, GetCurrentTokenType, GetCurrentToken,
GetChar, PutChar, OpenSource, CloseSource,
SkipUntilWhite, SkipWhite, SkipUntilEoln, AdvanceToken, IsReserved, PushBackToken,
SetDebugging ;
TYPE
TokenType = (identtok, literaltok, codetok, lbecomestok, rbecomestok, bartok, lsparatok, rsparatok,
lcparatok, rcparatok, lparatok, rparatok, errortok, tfunctok, symfunctok,
squotetok, dquotetok, moduletok, begintok, rulestok, endtok, lesstok, gretok,
tokentok, specialtok, firsttok, followtok, BNFtok, FNBtok, declarationtok,
epsilontok, eoftok) ;
(*
OpenSource - Attempts to open the source file, a.
The success of the operation is returned.
*)
PROCEDURE OpenSource (a: ARRAY OF CHAR) : BOOLEAN ;
(*
CloseSource - Closes the current open file.
*)
PROCEDURE CloseSource ;
(*
GetChar - returns the current character on the input stream.
*)
PROCEDURE GetChar () : CHAR ;
(*
PutChar - pushes a character onto the push back stack, it also
returns the character which has been pushed.
*)
PROCEDURE PutChar (ch: CHAR) : CHAR ;
(*
SymIs - if t is equal to the current token the next token is read
and true is returned, otherwise false is returned.
*)
PROCEDURE SymIs (t: TokenType) : BOOLEAN ;
(*
IsSym - returns the result of the comparison between the current token
type and t.
*)
PROCEDURE IsSym (t: TokenType) : BOOLEAN ;
(*
GetCurrentTokenType - returns the type of current token.
*)
PROCEDURE GetCurrentTokenType () : TokenType ;
(*
GetCurrentToken - returns the NameKey of the current token.
*)
PROCEDURE GetCurrentToken () : Name ;
(*
SkipUntilWhite - skips all characters until white space is seen.
*)
PROCEDURE SkipUntilWhite ;
(*
SkipWhite - skips all white space.
*)
PROCEDURE SkipWhite ;
(*
SkipUntilEoln - skips until a lf is seen. It consumes the lf.
*)
PROCEDURE SkipUntilEoln ;
(*
AdvanceToken - advances to the next token.
*)
PROCEDURE AdvanceToken ;
(*
IsReserved - returns TRUE if the name is a reserved word.
*)
PROCEDURE IsReserved (name: Name) : BOOLEAN ;
(*
PushBackToken - pushes a token back onto input.
*)
PROCEDURE PushBackToken (t: Name) ;
(*
SetDebugging - sets the debugging flag.
*)
PROCEDURE SetDebugging (flag: BOOLEAN) ;
END bnflex.
|
