1 /* $NetBSD: twalk.c,v 1.2 1999/09/16 11:45:37 lukem Exp $ */
2
3 /*
4 * Tree search generalized from Knuth (6.2.2) Algorithm T just like
5 * the AT&T man page says.
6 *
7 * The node_t structure is for internal use only, lint doesn't grok it.
8 *
9 * Written by reading the System V Interface Definition, not the code.
10 *
11 * Totally public domain.
12 */
13
14 #include <assert.h>
15 #define _SEARCH_PRIVATE
16 #include <search.h>
17 #include <stdlib.h>
18
19 static void trecurse (const node_t *, void (*action)(const void *, VISIT, int),
20 int level) __MINGW_ATTRIB_NONNULL (1)
21 __MINGW_ATTRIB_NONNULL (2);
22 /* Walk the nodes of a tree */
23 static void
trecurse(const node_t * root,void (* action)(const void *,VISIT,int),int level)24 trecurse (const node_t *root, /* Root of the tree to be walked */
25 void (*action)(const void *, VISIT, int),
26 int level)
27 {
28 if (root->llink == NULL && root->rlink == NULL)
29 (*action)(root, leaf, level);
30 else
31 {
32 (*action)(root, preorder, level);
33 if (root->llink != NULL)
34 trecurse (root->llink, action, level + 1);
35 (*action)(root, postorder, level);
36 if (root->rlink != NULL)
37 trecurse(root->rlink, action, level + 1);
38 (*action)(root, endorder, level);
39 }
40 }
41
42 /* Walk the nodes of a tree */
43 void
twalk(const void * vroot,void (* action)(const void *,VISIT,int))44 twalk (const void *vroot, /* Root of the tree to be walked */
45 void (*action) (const void *, VISIT, int))
46 {
47 if (vroot != NULL && action != NULL)
48 trecurse(vroot, action, 0);
49 }
50