[98474f] | 1 | // -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- |
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| 2 | /*****************************************************************************\ |
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| 3 | * Computer Algebra System SINGULAR |
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| 4 | \*****************************************************************************/ |
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| 5 | /** @file Enumerator.h |
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| 6 | * |
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| 7 | * Abstract API for enumerators. |
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| 8 | * |
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| 9 | * ABSTRACT: Abstract interface for forward iteratable containers (enumerators) |
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| 10 | * of standalone objects (e.g. polynomials as sets of numbers), without any |
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| 11 | * knowledge of their internals. |
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| 12 | * |
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| 13 | * @author Oleksandr Motsak |
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| 14 | * |
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| 15 | * |
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| 16 | **/ |
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| 17 | /*****************************************************************************/ |
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| 18 | |
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| 19 | #ifndef ENUMERATOR_H |
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| 20 | #define ENUMERATOR_H |
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| 21 | |
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| 22 | /** @class IBaseEnumerator |
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| 23 | * |
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| 24 | * Base enumerator interface for simple iteration over a generic non-empty collection. |
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| 25 | * |
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| 26 | * Abstract API of enumerators for non-empty enumerable collections of standalone |
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| 27 | * objects. Inspired by IEnumerator from C#. Usage parrten can be as |
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| 28 | * follows: |
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| 29 | * |
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| 30 | * @code |
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| 31 | * IBaseEnumerator itr = ...; |
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| 32 | * itr.Reset(); // goes to the first element (must exist) |
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| 33 | * do |
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| 34 | * { |
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| 35 | * do something custom with itr... |
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| 36 | * } |
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| 37 | * while( itr.MoveNext() ) |
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| 38 | * @endcode |
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| 39 | * |
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| 40 | * Note that the first element must exist and available directly after Reset() call. |
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| 41 | * |
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| 42 | * @sa IEnumerator |
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| 43 | */ |
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| 44 | class IBaseEnumerator // IDisposable |
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| 45 | { |
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| 46 | public: |
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| 47 | /// Advances the enumerator to the next element of the collection. |
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| 48 | /// returns true if the enumerator was successfully advanced to the |
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| 49 | /// next element; |
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| 50 | /// false if the enumerator has passed the end of the collection. |
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| 51 | virtual bool MoveNext() = 0; |
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| 52 | |
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| 53 | /// Sets the enumerator to its initial position, which is at the first element in the collection. |
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| 54 | virtual void Reset() = 0; |
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| 55 | // virtual ~IEnumerator() {} // TODO: needed? |
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| 56 | }; |
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| 57 | |
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| 58 | |
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| 59 | /** @class IAccessor |
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| 60 | * |
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| 61 | * Templated accessor interface for accessing individual data (for instance, of an enumerator). |
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| 62 | * |
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| 63 | * T is the type of objects to access, available via the Current() method. |
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| 64 | * |
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| 65 | * @sa IBaseEnumerator |
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| 66 | */ |
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| 67 | template <typename T> |
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| 68 | class IAccessor // IDisposable |
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| 69 | { |
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| 70 | public: |
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| 71 | typedef T value_type; |
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| 72 | typedef value_type& reference; |
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| 73 | typedef const value_type& const_reference; |
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| 74 | |
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| 75 | /// Gets the current element in the collection (read and write). |
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| 76 | virtual reference Current() = 0; |
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| 77 | |
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| 78 | /// Gets the current element in the collection (read only). |
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| 79 | virtual const_reference Current() const = 0; |
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| 80 | }; |
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| 81 | |
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| 82 | /** @class IEnumerator |
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| 83 | * |
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| 84 | * Templated enumerator interface for simple iteration over a generic non-empty collection of T's. |
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| 85 | * |
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| 86 | * Abstract API of enumerators for non-empty enumerable collections of standalone |
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| 87 | * objects. Inspired by IEnumerator from C#. Usage parrten can be as |
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| 88 | * follows: |
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| 89 | * |
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| 90 | * @code |
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| 91 | * IEnumerator<T> itr = ...; |
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| 92 | * itr.Reset(); // goes to the first element (must exist) |
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| 93 | * do |
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| 94 | * { |
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| 95 | * use/change itr.Current()... |
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| 96 | * } |
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| 97 | * while( itr.MoveNext() ) |
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| 98 | * @endcode |
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| 99 | * |
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| 100 | * T is the type of objects to enumerate, available via Current() method |
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| 101 | * |
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| 102 | * @sa IBaseEnumerator |
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| 103 | */ |
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| 104 | template <typename T> |
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| 105 | class IEnumerator: public virtual IBaseEnumerator, public virtual IAccessor<T> |
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| 106 | { |
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| 107 | public: |
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| 108 | }; |
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| 109 | |
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| 110 | #if 0 |
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| 111 | // the following is not used for now // |
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| 112 | // the following is not used for now // |
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| 113 | // the following is not used for now // |
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| 114 | // the following is not used for now // |
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| 115 | // the following is not used for now // |
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| 116 | |
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| 117 | // include basic definitions |
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| 118 | //??// #include <iterator> |
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| 119 | |
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| 120 | /** @class IBaseIterator |
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| 121 | * |
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| 122 | * A base abstract iterator API with virtualized standard iterator operators |
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| 123 | * |
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| 124 | * Abstract API for iterators that should work with STL and BOOST. |
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| 125 | * |
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| 126 | * @sa STL iterators |
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| 127 | */ |
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| 128 | template <class A> |
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| 129 | class IBaseIterator //??// : public std::iterator<std::forward_iterator_tag, A> |
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| 130 | { |
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| 131 | public: |
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| 132 | typedef IBaseIterator<A> self; |
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| 133 | typedef self& self_reference; |
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| 134 | typedef const self_reference const_self_reference; |
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| 135 | |
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| 136 | virtual bool operator==(const_self_reference rhs) = 0; |
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| 137 | |
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| 138 | /// ++itr, goes to the next state, returns the new state |
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| 139 | virtual self_reference operator++() = 0; |
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| 140 | |
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| 141 | /// itr++, goes to the next state, returns the previous state |
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| 142 | virtual self_reference operator++(int) = 0; |
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| 143 | |
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| 144 | virtual A& operator*() = 0; |
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| 145 | virtual A* operator->() = 0; |
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| 146 | |
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| 147 | inline bool operator!=(const_self_reference rhs){ return !((*this) == rhs); } |
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| 148 | }; |
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| 149 | |
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| 150 | /** @class AIterator |
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| 151 | * |
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| 152 | * An abstract iterator with virtualized assigment operator and |
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| 153 | * constructors. |
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| 154 | * |
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| 155 | * Abstract API for iterators that should work with STL and BOOST. |
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| 156 | * |
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| 157 | * @sa STL iterators |
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| 158 | */ |
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| 159 | template <class A> |
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| 160 | class IIterator: public IBaseIterator<A> |
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| 161 | { |
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| 162 | public: |
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| 163 | typedef IIterator<A> self; |
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| 164 | typedef self& self_reference; |
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| 165 | typedef const self_reference const_self_reference; |
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| 166 | |
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| 167 | IIterator(){ void_constructor(); } |
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| 168 | |
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| 169 | IIterator(const_self_reference itr) { copy_constructor(itr); } |
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| 170 | |
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| 171 | virtual self_reference operator=(const_self_reference other) = 0; |
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| 172 | |
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| 173 | private: |
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| 174 | virtual void void_constructor() = 0; |
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| 175 | virtual void copy_constructor(const_self_reference itr) = 0; |
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| 176 | }; |
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| 177 | |
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| 178 | /** @class IContainer |
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| 179 | * |
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| 180 | * Container of standalone objects |
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| 181 | * |
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| 182 | * Abstract API for containers of objects and their iterators |
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| 183 | * |
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| 184 | * @sa STL containers and iterators |
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| 185 | */ |
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| 186 | template <class T> |
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| 187 | class IContainer |
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| 188 | { |
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| 189 | public: |
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| 190 | typedef T value_type; |
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| 191 | typedef value_type& reference; |
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| 192 | typedef const value_type& const_reference; |
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| 193 | //??// typedef std::size_t size_type; |
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| 194 | //??// virtual size_type size() const = 0; |
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| 195 | virtual bool empty() const = 0; |
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| 196 | |
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| 197 | typedef IIterator<reference> iterator; |
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| 198 | virtual iterator begin() = 0; |
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| 199 | virtual iterator end() = 0; |
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| 200 | |
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| 201 | typedef IIterator<const_reference> const_iterator; |
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| 202 | virtual const_iterator begin() const = 0; |
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| 203 | virtual const_iterator end() const = 0; |
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| 204 | }; |
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| 205 | #endif |
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| 206 | |
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| 207 | |
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| 208 | #endif |
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| 209 | /* #ifndef ENUMERATOR_H */ |
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| 210 | |
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| 211 | // Vi-modeline: vim: filetype=c:syntax:shiftwidth=2:tabstop=8:textwidth=0:expandtab |
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