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[mLib] / sym.h
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0875b58f 1/* -*-c-*-
2 *
03d53b73 3 * $Id: sym.h,v 1.8 1999/08/02 14:45:48 mdw Exp $
0875b58f 4 *
5 * Symbol table management
6 *
7 * (c) 1998 Straylight/Edgeware
8 */
9
c846879c 10/*----- Licensing notice --------------------------------------------------*
0875b58f 11 *
12 * This file is part of the mLib utilities library.
13 *
14 * mLib is free software; you can redistribute it and/or modify
c846879c 15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
18 *
0875b58f 19 * mLib 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
c846879c 22 * GNU Library General Public License for more details.
23 *
24 * You should have received a copy of the GNU Library General Public
0bd98442 25 * License along with mLib; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
27 * MA 02111-1307, USA.
0875b58f 28 */
29
30/*----- Revision history --------------------------------------------------*
31 *
32 * $Log: sym.h,v $
03d53b73 33 * Revision 1.8 1999/08/02 14:45:48 mdw
34 * Break low-level hashtable code out from sym.
35 *
d4d7a053 36 * Revision 1.7 1999/06/01 09:49:33 mdw
37 * Allow things to be looked up by just their caller-supplied hashes. This
38 * actually needs to be thought through better.
39 *
34b97201 40 * Revision 1.6 1999/05/26 21:08:31 mdw
41 * Rename symbols in line with newer conventions.
42 *
8c6d948b 43 * Revision 1.5 1999/05/13 22:48:37 mdw
44 * Change `-ise' to `-ize' throughout.
45 *
0bd98442 46 * Revision 1.4 1999/05/06 19:51:35 mdw
47 * Reformatted the LGPL notice a little bit.
48 *
c846879c 49 * Revision 1.3 1999/05/05 18:50:31 mdw
50 * Change licensing conditions to LGPL.
51 *
a5d14ede 52 * Revision 1.2 1998/11/26 19:27:34 mdw
53 * Move SYM_NAME into the header file. Fix bugs.
54 *
55 * Revision 1.1.1.1 1998/06/17 23:44:42 mdw
56 * Initial version of mLib
0875b58f 57 *
58 */
59
60#ifndef SYM_H
61#define SYM_H
62
63#ifdef __cplusplus
64 extern "C" {
65#endif
66
67/*----- Required headers --------------------------------------------------*/
68
69#include <stddef.h>
70
d4d7a053 71#ifndef BITS_H
72# include "bits.h"
73#endif
74
03d53b73 75#ifndef HASH_H
76# include "hash.h"
77#endif
78
0875b58f 79/*----- Type definitions --------------------------------------------------*/
80
81/* --- Symbol table --- *
82 *
83 * A @sym_table@ contains the information needed to manage a symbol table.
84 * Users shouldn't fiddle with this information directly, but it needs to be
85 * here so that objects of the correct type can be created.
86 */
87
88typedef struct sym_table {
03d53b73 89 hash_table t;
90 size_t load;
0875b58f 91} sym_table;
92
93/* --- A symbol table entry --- *
94 *
95 * I don't care what actually gets stored in symbol entries because I don't
96 * create them: that's the responsibility of my client. All I care about
97 * here is that whatever gets passed to me is a structure whose first member
98 * is a @sym_base@. The ANSI guarantees about structure layout are
99 * sufficient to allow me to manipulate such objects.
100 */
101
102#define SYM_BUFSZ 16 /* Size of local string buffer */
103
104typedef struct sym_base {
03d53b73 105 hash_base b;
0875b58f 106 union {
107 char *p; /* Pointer to name string */
108 char b[SYM_BUFSZ]; /* Buffer containing a short name */
109 } name; /* Name of this symbol */
110 size_t len; /* Length of the symbol's name */
111} sym_base;
112
a5d14ede 113/* --- A macro to pick a symbol's name out from the mess --- */
114
115#define SYM_NAME(sy) \
116 (((sym_base *)(sy))->len > SYM_BUFSZ ? \
117 ((sym_base *)(sy))->name.p : \
118 ((sym_base *)(sy))->name.b)
119
0875b58f 120/* --- An iterator block --- */
121
03d53b73 122typedef hash_iter sym_iter;
0875b58f 123
124/*----- External functions ------------------------------------------------*/
125
34b97201 126/* --- @sym_create@ --- *
0875b58f 127 *
8c6d948b 128 * Arguments: @sym_table *t@ = symbol table to initialize
0875b58f 129 *
130 * Returns: ---
131 *
8c6d948b 132 * Use: Initializes the given symbol table. Raises @EXC_NOMEM@ if
0875b58f 133 * there isn't enough memory.
134 */
135
34b97201 136extern void sym_create(sym_table */*t*/);
0875b58f 137
34b97201 138/* --- @sym_destroy@ --- *
0875b58f 139 *
140 * Arguments: @sym_table *t@ = pointer to symbol table in question
141 *
142 * Returns: ---
143 *
144 * Use: Destroys a symbol table, freeing all the memory it used to
145 * occupy.
146 */
147
34b97201 148extern void sym_destroy(sym_table */*t*/);
0875b58f 149
150/* --- @sym_find@ --- *
151 *
152 * Arguments: @sym_table *t@ = pointer to symbol table in question
153 * @const char *n@ = pointer to symbol table to look up
154 * @long l@ = length of the name string or negative to measure
155 * @size_t sz@ = size of desired symbol object, or zero
156 * @unsigned *f@ = pointer to a flag, or null.
157 *
158 * Returns: The address of a @sym_base@ structure, or null if not found
159 * and @sz@ is zero.
160 *
161 * Use: Looks up a symbol in a given symbol table. The name is
162 * passed by the address of its first character. The length
163 * may be given, in which case the name may contain arbitrary
164 * binary data, or it may be given as a negative number, in
165 * which case the length of the name is calculated as
03d53b73 166 * @strlen(n) + 1@.
0875b58f 167 *
168 * The return value is the address of a pointer to a @sym_base@
169 * block (which may have other things on the end, as above). If
170 * the symbol could be found, the return value points to the
171 * symbol block. If the symbol wasn't there, then if @sz@ is
172 * nonzero, a new symbol is created and its address is returned;
173 * otherwise a null pointer is returned. The exception
174 * @EXC_NOMEM@ is raised if the block can't be allocated.
175 *
176 * The value of @*f@ indicates whether a new symbol entry was
177 * created: a nonzero value indicates that an old value was
178 * found.
179 */
180
181extern void *sym_find(sym_table */*t*/, const char */*n*/, long /*l*/,
182 size_t /*sz*/, unsigned */*f*/);
183
184/* --- @sym_remove@ --- *
185 *
186 * Arguments: @sym_table *i@ = pointer to a symbol table object
187 * @void *b@ = pointer to symbol table entry
188 *
189 * Returns: ---
190 *
191 * Use: Removes the object from the symbol table. The space occupied
192 * by the object and its name is freed; anything else attached
193 * to the entry should already be gone by this point.
194 */
195
196extern void sym_remove(sym_table */*t*/, void */*b*/);
197
34b97201 198/* --- @sym_mkiter@ --- *
0875b58f 199 *
200 * Arguments: @sym_iter *i@ = pointer to an iterator object
201 * @sym_table *t@ = pointer to a symbol table object
202 *
203 * Returns: ---
204 *
205 * Use: Creates a new symbol table iterator which may be used to
206 * iterate through a symbol table.
207 */
208
03d53b73 209#define SYM_MKITER(i, t) HASH_MKITER((i), &(t)->t)
210
34b97201 211extern void sym_mkiter(sym_iter */*i*/, sym_table */*t*/);
0875b58f 212
213/* --- @sym_next@ --- *
214 *
215 * Arguments: @sym_iter *i@ = pointer to iterator object
216 *
217 * Returns: Pointer to the next symbol found, or null when finished.
218 *
219 * Use: Returns the next symbol from the table. Symbols are not
220 * returned in any particular order.
221 */
222
03d53b73 223#define SYM_NEXT(i, p) do { \
224 hash_base *_q; \
225 HASH_NEXT((i), _q); \
226 (p) = (void *)_q; \
227} while (0)
228
0875b58f 229extern void *sym_next(sym_iter */*i*/);
230
231/*----- That's all, folks -------------------------------------------------*/
232
233#ifdef __cplusplus
234 }
235#endif
236
237#endif