3 * $Id: assoc.h,v 1.2 2001/01/25 21:12:22 mdw Exp $
7 * (c) 2000 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the mLib utilities library.
14 * mLib is free software; you can redistribute it and/or modify
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.
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
22 * GNU Library General Public License for more details.
24 * You should have received a copy of the GNU Library General Public
25 * License along with mLib; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.2 2001/01/25 21:12:22 mdw
34 * Add new macro to find an association's atom key.
36 * Revision 1.1 2001/01/20 11:50:58 mdw
37 * Hash tables indexed by atoms, to avoid expense of hashing keys on each
38 * lookup, and to reduce storage used by key texts.
49 /*----- Header files ------------------------------------------------------*/
59 /*----- Data structures ---------------------------------------------------*/
61 typedef struct assoc_table {
66 typedef struct assoc_base {
71 typedef struct { hash_iter i; } assoc_iter;
73 #define ASSOC_ATOM(p) (((assoc_base *)(p))->a + 0)
75 /*----- Functions provided ------------------------------------------------*/
77 /* --- @assoc_create@ --- *
79 * Arguments: @assoc_table *t@ = pointer to an association table
83 * Use: Creates a new association table.
86 extern void assoc_create(assoc_table */*t*/);
88 /* --- @assoc_destroy@ --- *
90 * Arguments: @assoc_table *t@ = pointer to an association table
94 * Use: Destroys an association table.
97 extern void assoc_destroy(assoc_table */*t*/);
99 /* --- @assoc_find@ --- *
101 * Arguments: @assoc_table *t@ = pointer to an association table
102 * @atom *a@ = an atom to label the item
103 * @size_t sz@ = size of block to allocate
104 * @unsigned *f@ = pointer to `found' flag
106 * Returns: A pointer to the item located or null.
108 * Use: Looks up an atom in an association table. If the atom is
109 * found, the association is returned. If not, and @sz@ is
110 * zero, a null pointer is returned. Otherwise, a block of size
111 * @sz@ is allocated, its @assoc_base@ header is filled in, and
112 * the pointer returned. The flag @*f@ is cleared if the item
113 * couldn't be found, or set if it was.
115 * All the atoms used in a particular table should
118 extern void *assoc_find(assoc_table */*t*/, atom */*a*/,
119 size_t /*sz*/, unsigned */*f*/);
121 /* --- @assoc_remove@ --- *
123 * Arguments: @assoc_table *t@ = pointer to an association table
124 * @void *p@ = pointer to a block to remove
128 * Use: Removes an association from a table.
131 extern void assoc_remove(assoc_table */*t*/, void */*p*/);
133 /* --- @assoc_mkiter@, @assoc_next@ --- *
135 * Arguments: @assoc_iter *i@ = pointer to an iterator
136 * @assoc_table *t@ = pointer to an association table
138 * Returns: Next association, or null, for @assoc_next@; nothing for
141 * Use: Iterates over the associations in a table.
144 #define ASSOC_MKITER(i_, t_) HASH_MKITER(&(i_)->i, &(t_)->t)
146 #define ASSOC_NEXT(i_, p) do { \
148 HASH_NEXT(&(i_)->i, _q); \
152 extern void assoc_mkiter(assoc_iter */*i*/, assoc_table */*t*/);
153 extern void *assoc_next(assoc_iter */*i*/);
155 /*----- That's all, folks -------------------------------------------------*/