| 1 | /*
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| 2 | Copyright (c) 2003-2006, Troy Aaron Johnson
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| 3 | All rights reserved.
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| 4 |
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| 5 | Redistribution and use in source and binary forms, with or without
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| 6 | modification, are permitted provided that the following conditions
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| 7 | are met:
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| 8 |
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| 9 | * Redistributions of source code must retain the above copyright
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| 10 | notice, this list of conditions and the following disclaimer.
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| 11 | * Redistributions in binary form must reproduce the above copyright
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| 12 | notice, this list of conditions and the following disclaimer in the
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| 13 | documentation and/or other materials provided with the distribution.
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| 14 | * Neither the name of Troy Aaron Johnson nor the names of any
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| 15 | contributors may be used to endorse or promote products derived from
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| 16 | this software without specific prior written permission.
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| 17 |
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| 18 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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| 19 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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| 20 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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| 21 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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| 22 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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| 23 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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| 24 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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| 25 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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| 26 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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| 27 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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| 28 | POSSIBILITY OF SUCH DAMAGE.
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| 29 | */
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| 30 |
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| 31 | /** The base template for all iterators.
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| 32 | */
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| 33 | template <class T, class R, class P>
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| 34 | class tree_iterator
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| 35 | {
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| 36 | friend class tree;
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| 37 |
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| 38 | protected:
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| 39 |
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| 40 | /* The node pointed to by this iterator. */
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| 41 | tree_node<N>* current;
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| 42 |
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| 43 | /* This is the depth of an iterator relative to its starting position.
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| 44 | The starting depth is 0, the depth of the parent is -1, the depth
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| 45 | of any child is 1, the depth of any grandchild is 2, etc. */
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| 46 | long iter_depth;
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| 47 |
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| 48 | /** Allows derived classes to create an iterator
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| 49 | * from a pointer to a node. This constructor
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| 50 | * is not explicit because the tree_iterator class
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| 51 | * contains the == and != operators, which are used
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| 52 | * throughout the template to compare iterators
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| 53 | * to NULL. The tree_iterator class is not visible
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| 54 | * to the user, so this implicit constructor is
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| 55 | * entirely for my convenience when coding the template.
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| 56 | *
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| 57 | * @param current Position for the new iterator
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| 58 | */
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| 59 | tree_iterator(tree_node<N>* current) : current(current), iter_depth(0L) { }
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| 60 |
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| 61 | /** Destroys the node pointed to by this iterator.
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| 62 | */
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| 63 | void destroy(void)
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| 64 | {
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| 65 | delete current;
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| 66 | current = NULL;
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| 67 | iter_depth = 0L;
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| 68 | }
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| 69 |
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| 70 | /* increment and decrement methods used by both the iterator
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| 71 | and the const_iterator versions of various iterators */
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| 72 |
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| 73 | static inline void post_inc(tree_node<N>*& current, long& depth);
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| 74 | static inline void post_dec(tree_node<N>*& current, long& depth);
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| 75 |
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| 76 | static inline void pre_inc(tree_node<N>*& current, long& depth);
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| 77 | static inline void pre_dec(tree_node<N>*& current, long& depth);
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| 78 |
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| 79 | static inline void sib_inc(tree_node<N>*& current);
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| 80 | static inline void sib_dec(tree_node<N>*& current);
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| 81 |
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| 82 | public:
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| 83 |
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| 84 | /* The following typedefs are required for compatibility
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| 85 | * with standard containers. */
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| 86 |
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| 87 | typedef std::bidirectional_iterator_tag iterator_category;
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| 88 | typedef T value_type;
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| 89 | typedef R reference;
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| 90 | typedef P pointer;
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| 91 | typedef size_t size_type;
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| 92 | typedef ptrdiff_t difference_type;
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| 93 |
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| 94 | tree_iterator(void) : current(NULL), iter_depth(0L) { }
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| 95 |
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| 96 | tree_iterator(const tree_iterator& iter)
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| 97 | : current(iter.current), iter_depth(iter.iter_depth) { }
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| 98 |
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| 99 | /* note that depth is not relevant when comparing iterators */
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| 100 |
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| 101 | bool operator == (const tree_iterator& iter) const
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| 102 | { return this->current == iter.current; }
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| 103 |
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| 104 | bool operator != (const tree_iterator& iter) const
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| 105 | { return this->current != iter.current; }
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| 106 |
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| 107 | long depth(void) const { return iter_depth; }
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| 108 |
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| 109 | bool leaf(void) const { return this->first_child == NULL; }
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| 110 | };
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