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
19static 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 */
23static void
24trecurse (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 */
43void
44twalk (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}