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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: scan.h,v 1.2 1999/07/26 23:24:33 mdw Exp $ |
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4 | * |
5 | * Character scanners |
6 | * |
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7 | * (c) 1999 Straylight/Edgeware |
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8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of the `fw' port forwarder. |
13 | * |
14 | * `fw' is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * `fw' is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with `fw'; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: scan.h,v $ |
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32 | * Revision 1.2 1999/07/26 23:24:33 mdw |
33 | * Complete rewrite. Allow a list of character sources to enable changes |
34 | * during parsing of syntactic constructs. |
35 | * |
36 | * Revision 1.1.1.1 1999/07/01 08:56:23 mdw |
37 | * Initial revision. |
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38 | * |
39 | */ |
40 | |
41 | #ifndef SCAN_H |
42 | #define SCAN_H |
43 | |
44 | #ifdef __cplusplus |
45 | extern "C" { |
46 | #endif |
47 | |
48 | /*----- Header files ------------------------------------------------------*/ |
49 | |
50 | #include <stdio.h> |
51 | |
52 | #include <mLib/dstr.h> |
53 | |
54 | /*----- Data structures ---------------------------------------------------*/ |
55 | |
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56 | /* --- A low-level scanner source --- */ |
57 | |
58 | typedef struct scansrc { |
59 | struct scansrc *next; /* Next one in the list */ |
60 | struct scansrc_ops *ops; /* Pointer to operations table */ |
61 | char *src; /* Name of this source */ |
62 | int line; /* Current line number */ |
63 | int pushback; /* Pushback character */ |
64 | char *tok; /* Token pushback */ |
65 | unsigned t; /* Token type pushback */ |
66 | } scansrc; |
67 | |
68 | /* --- Scanner source operations --- */ |
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69 | |
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70 | typedef struct scansrc_ops { |
71 | int (*scan)(scansrc */*ss*/); /* Read another character */ |
72 | void (*destroy)(scansrc */*ss*/); /* Destroy an unwanted source */ |
73 | } scansrc_ops; |
74 | |
75 | /* --- A character scanner --- */ |
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76 | |
77 | typedef struct scanner { |
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78 | scansrc *head, **tail; /* Scanner list head and tail */ |
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79 | int t; /* Token type */ |
80 | dstr d; /* Current token value */ |
81 | } scanner; |
82 | |
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83 | /*----- Particular scanner types ------------------------------------------*/ |
84 | |
85 | /* --- @scan_file@ --- * |
86 | * |
87 | * Arguments: @FILE *fp@ = pointer to file descriptor |
88 | * @char *name@ = pointer to source file name |
89 | * @unsigned f@ = flags |
90 | * |
91 | * Returns: A scanner source. |
92 | * |
93 | * Use: Creates a new scanner source for reading from a file. |
94 | */ |
95 | |
96 | extern scansrc *scan_file(FILE */*fp*/, char */*name*/, unsigned /*f*/); |
97 | |
98 | #define SCF_NOCLOSE 1u |
99 | #define SCF_FREENAME 2u |
100 | |
101 | /* --- @scan_argv@ --- * |
102 | * |
103 | * Arguments: @char **av@ = pointer to argument array (null terminated) |
104 | * |
105 | * Returns: A scanner source. |
106 | * |
107 | * Use: Creates a new scanner source for reading from an @argv@ |
108 | * array. |
109 | */ |
110 | |
111 | extern scansrc *scan_argv(char **/*av*/); |
112 | |
113 | /*----- General scanner handling ------------------------------------------*/ |
114 | |
115 | /* --- @scan@ --- * |
116 | * |
117 | * Arguments: @scanner *sc@ = pointer to main scanner context |
118 | * |
119 | * Returns: Character read, or end-of-file. |
120 | * |
121 | * Use: Scans a character from a source of characters. |
122 | */ |
123 | |
124 | extern int scan(scanner */*sc*/); |
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125 | |
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126 | /* --- @unscan@ --- * |
127 | * |
128 | * Arguments: @scanner *sc@ = pointer to main scanner context |
129 | * @int ch@ = character to unscan |
130 | * |
131 | * Returns: --- |
132 | * |
133 | * Use: Scans a character from a source of characters. |
134 | */ |
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135 | |
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136 | extern void unscan(scanner */*sc*/, int /*ch*/); |
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137 | |
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138 | /* --- @scan_push@ --- * |
139 | * |
140 | * Arguments: @scanner *sc@ = pointer to main scanner context |
141 | * @scansrc *ss@ = souorce to push |
142 | * |
143 | * Returns: --- |
144 | * |
145 | * Use: Pushes a scanner source onto the front of the queue. |
146 | */ |
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147 | |
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148 | extern void scan_push(scanner */*sc*/, scansrc */*ss*/); |
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149 | |
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150 | /* --- @scan_add@ --- * |
151 | * |
152 | * Arguments: @scanner *sc@ = pointer to main scanner context |
153 | * @scansrc *ss@ = souorce to push |
154 | * |
155 | * Returns: --- |
156 | * |
157 | * Use: Adds a scanner source onto the end of the queue. |
158 | */ |
159 | |
160 | extern void scan_add(scanner */*sc*/, scansrc */*ss*/); |
161 | |
162 | /* --- @scan_create@ --- * |
163 | * |
164 | * Arguments: @scanner *sc@ = scanner context to initialize |
165 | * |
166 | * Returns: --- |
167 | * |
168 | * Use: Initializes a scanner block ready for use. |
169 | */ |
170 | |
171 | extern void scan_create(scanner */*sc*/); |
172 | |
173 | /* --- @scan_destroy@ --- * |
174 | * |
175 | * Arguments: @scanner *sc@ = pointer to scanner context |
176 | * |
177 | * Returns: --- |
178 | * |
179 | * Use: Destroys a scanner and all the sources attached to it. |
180 | */ |
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181 | |
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182 | extern void scan_destroy(scanner */*sc*/); |
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183 | |
184 | /*----- That's all, folks -------------------------------------------------*/ |
185 | |
186 | #ifdef __cplusplus |
187 | } |
188 | #endif |
189 | |
190 | #endif |