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Initial import from lwtools 3.0.1 version, with new hand built build system and file reorganization
author lost@l-w.ca
date Wed, 19 Jan 2011 22:27:17 -0700
parents
children 7317fbe024af
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-1:000000000000 0:2c24602be78f
1 /*
2 lw_stack.c
3
4 Copyright © 2010 William Astle
5
6 This file is part of LWTOOLS.
7
8 LWTOOLS is free software: you can redistribute it and/or modify it under the
9 terms of the GNU General Public License as published by the Free Software
10 Foundation, either version 3 of the License, or (at your option) any later
11 version.
12
13 This program is distributed in the hope that it will be useful, but WITHOUT
14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 more details.
17
18 You should have received a copy of the GNU General Public License along with
19 this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22 #define ___lw_stack_c_seen___
23 #include "lw_stack.h"
24 #include "lw_alloc.h"
25
26 /* this is technically valid but dubious */
27 #define NULL 0
28
29 lw_stack_t lw_stack_create(void (*freefn)(void *d))
30 {
31 lw_stack_t S;
32
33 S = lw_alloc(sizeof(lw_stack_t));
34 S -> head = NULL;
35 S -> freefn = freefn;
36 return S;
37 }
38
39 void *lw_stack_pop(lw_stack_t S)
40 {
41 if (S -> head)
42 {
43 void *ret, *r2;
44
45 ret = S -> head -> data;
46 r2 = S -> head;
47 S -> head = S -> head -> next;
48 lw_free(r2);
49 return ret;
50 }
51 return NULL;
52 }
53
54 void lw_stack_destroy(lw_stack_t S)
55 {
56 void *d;
57
58 while (d = lw_stack_pop(S))
59 (S->freefn)(d);
60 lw_free(S);
61 }
62
63 void *lw_stack_top(lw_stack_t S)
64 {
65 if (S -> head)
66 return S -> head -> data;
67 return NULL;
68 }
69
70 void lw_stack_push(lw_stack_t S, void *item)
71 {
72 struct lw_stack_node_priv *t;
73
74 t = lw_alloc(sizeof(struct lw_stack_node_priv));
75 t -> next = S -> head;
76 S -> head = t;
77 t -> data = item;
78 }