54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
/* $NetBSD: twalk.c,v 1.4 2012/03/20 16:38:45 matt Exp $ */
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/*
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* Tree search generalized from Knuth (6.2.2) Algorithm T just like
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* the AT&T man page says.
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*
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* The node_t structure is for internal use only, lint doesn't grok it.
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*
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* Written by reading the System V Interface Definition, not the code.
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*
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* Totally public domain.
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*/
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#include <sys/cdefs.h>
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#if defined(LIBC_SCCS) && !defined(lint)
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__RCSID("$NetBSD: twalk.c,v 1.4 2012/03/20 16:38:45 matt Exp $");
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#endif /* LIBC_SCCS and not lint */
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#include <assert.h>
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#define _SEARCH_PRIVATE
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#include <search.h>
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#include <stdlib.h>
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typedef void (*cmp_fn_t)(const void *, VISIT, int);
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/* Walk the nodes of a tree */
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static void
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trecurse(const node_t *root, /* Root of the tree to be walked */
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cmp_fn_t action, int level)
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{
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_DIAGASSERT(root != NULL);
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_DIAGASSERT(action != NULL);
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if (root->llink == NULL && root->rlink == NULL)
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(*action)(root, leaf, level);
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else {
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(*action)(root, preorder, level);
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if (root->llink != NULL)
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trecurse(root->llink, action, level + 1);
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(*action)(root, postorder, level);
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if (root->rlink != NULL)
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trecurse(root->rlink, action, level + 1);
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(*action)(root, endorder, level);
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}
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}
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/* Walk the nodes of a tree */
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void
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twalk(const void *vroot, cmp_fn_t action) /* Root of the tree to be walked */
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{
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if (vroot != NULL && action != NULL)
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trecurse(vroot, action, 0);
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}
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