Gabriele Cosmo
111 lines
4.2 KiB
C++
111 lines
4.2 KiB
C++
/*
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Copyright (c) 2003-2006, Troy Aaron Johnson
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the name of Troy Aaron Johnson nor the names of any
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contributors may be used to endorse or promote products derived from
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this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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/** The base template for all iterators.
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*/
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template <class T, class R, class P>
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class tree_iterator
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{
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friend class tree;
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protected:
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/* The node pointed to by this iterator. */
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tree_node<N>* current;
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/* This is the depth of an iterator relative to its starting position.
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The starting depth is 0, the depth of the parent is -1, the depth
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of any child is 1, the depth of any grandchild is 2, etc. */
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long iter_depth;
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/** Allows derived classes to create an iterator
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* from a pointer to a node. This constructor
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* is not explicit because the tree_iterator class
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* contains the == and != operators, which are used
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* throughout the template to compare iterators
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* to NULL. The tree_iterator class is not visible
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* to the user, so this implicit constructor is
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* entirely for my convenience when coding the template.
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*
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* @param current Position for the new iterator
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*/
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tree_iterator(tree_node<N>* current) : current(current), iter_depth(0L) { }
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/** Destroys the node pointed to by this iterator.
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*/
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void destroy(void)
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{
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delete current;
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current = NULL;
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iter_depth = 0L;
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}
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/* increment and decrement methods used by both the iterator
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and the const_iterator versions of various iterators */
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static inline void post_inc(tree_node<N>*& current, long& depth);
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static inline void post_dec(tree_node<N>*& current, long& depth);
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static inline void pre_inc(tree_node<N>*& current, long& depth);
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static inline void pre_dec(tree_node<N>*& current, long& depth);
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static inline void sib_inc(tree_node<N>*& current);
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static inline void sib_dec(tree_node<N>*& current);
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public:
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/* The following typedefs are required for compatibility
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* with standard containers. */
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typedef std::bidirectional_iterator_tag iterator_category;
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typedef T value_type;
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typedef R reference;
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typedef P pointer;
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typedef size_t size_type;
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typedef ptrdiff_t difference_type;
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tree_iterator(void) : current(NULL), iter_depth(0L) { }
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tree_iterator(const tree_iterator& iter)
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: current(iter.current), iter_depth(iter.iter_depth) { }
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/* note that depth is not relevant when comparing iterators */
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bool operator == (const tree_iterator& iter) const
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{ return this->current == iter.current; }
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bool operator != (const tree_iterator& iter) const
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{ return this->current != iter.current; }
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long depth(void) const { return iter_depth; }
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bool leaf(void) const { return this->first_child == NULL; }
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};
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