/* Binary tree data structure.
Copyright (C) 2006, 2015-2016 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef _TSEARCH_H
#define _TSEARCH_H
#if HAVE_TSEARCH
/* Get tseach(), tfind(), tdelete(), twalk() declarations. */
#include <search.h>
#else
#ifdef __cplusplus
extern "C" {
#endif
/* See <http://www.opengroup.org/susv3xbd/search.h.html>,
<http://www.opengroup.org/susv3xsh/tsearch.html>
for details. */
typedef enum
{
preorder,
postorder,
endorder,
leaf
}
VISIT;
/* Searches an element in the tree *VROOTP that compares equal to KEY.
If one is found, it is returned. Otherwise, a new element equal to KEY
is inserted in the tree and is returned. */
extern void * tsearch (const void *key, void **vrootp,
int (*compar) (const void *, const void *));
/* Searches an element in the tree *VROOTP that compares equal to KEY.
If one is found, it is returned. Otherwise, NULL is returned. */
extern void * tfind (const void *key, void *const *vrootp,
int (*compar) (const void *, const void *));
/* Searches an element in the tree *VROOTP that compares equal to KEY.
If one is found, it is removed from the tree, and its parent node is
returned. Otherwise, NULL is returned. */
extern void * tdelete (const void *key, void **vrootp,
int (*compar) (const void *, const void *));
/* Perform a depth-first, left-to-right traversal of the tree VROOT.
The ACTION function is called:
- for non-leaf nodes: 3 times, before the left subtree traversal,
after the left subtree traversal but before the right subtree traversal,
and after the right subtree traversal,
- for leaf nodes: once.
The arguments passed to ACTION are:
1. the node; it can be casted to a 'const void * const *', i.e. into a
pointer to the key,
2. an indicator which visit of the node this is,
3. the level of the node in the tree (0 for the root). */
extern void twalk (const void *vroot,
void (*action) (const void *, VISIT, int));
#ifdef __cplusplus
}
#endif
#endif
#endif /* _TSEARCH_H */
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