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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