[1337] | 1 | // (C) Copyright Joel de Guzman 2003. |
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| 2 | // Distributed under the Boost Software License, Version 1.0. (See |
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| 3 | // accompanying file LICENSE_1_0.txt or copy at |
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| 4 | // http://www.boost.org/LICENSE_1_0.txt) |
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| 5 | |
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| 6 | #ifndef INDEXING_SUITE_JDG20036_HPP |
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| 7 | # define INDEXING_SUITE_JDG20036_HPP |
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| 8 | |
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| 9 | # include <boost/python/class.hpp> |
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| 10 | # include <boost/python/def_visitor.hpp> |
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| 11 | # include <boost/python/register_ptr_to_python.hpp> |
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| 12 | # include "detail/indexing_suite_detail.hpp" |
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| 13 | # include <boost/python/return_internal_reference.hpp> |
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| 14 | # include <boost/python/iterator.hpp> |
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| 15 | # include <boost/mpl/or.hpp> |
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| 16 | # include <boost/mpl/not.hpp> |
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| 17 | |
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| 18 | namespace boost { namespace python { |
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| 19 | |
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| 20 | // indexing_suite class. This class is the protocol class for |
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| 21 | // the management of C++ containers intended to be integrated |
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| 22 | // to Python. The objective is make a C++ container look and |
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| 23 | // feel and behave exactly as we'd expect a Python container. |
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| 24 | // By default indexed elements are returned by proxy. This can be |
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| 25 | // disabled by supplying *true* in the NoProxy template parameter. |
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| 26 | // |
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| 27 | // Derived classes provide the hooks needed by the indexing_suite |
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| 28 | // to do its job: |
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| 29 | // |
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| 30 | // static data_type& |
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| 31 | // get_item(Container& container, index_type i); |
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| 32 | // |
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| 33 | // static object |
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| 34 | // get_slice(Container& container, index_type from, index_type to); |
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| 35 | // |
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| 36 | // static void |
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| 37 | // set_item(Container& container, index_type i, data_type const& v); |
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| 38 | // |
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| 39 | // static void |
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| 40 | // set_slice( |
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| 41 | // Container& container, index_type from, |
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| 42 | // index_type to, data_type const& v |
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| 43 | // ); |
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| 44 | // |
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| 45 | // template <class Iter> |
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| 46 | // static void |
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| 47 | // set_slice(Container& container, index_type from, |
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| 48 | // index_type to, Iter first, Iter last |
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| 49 | // ); |
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| 50 | // |
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| 51 | // static void |
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| 52 | // delete_item(Container& container, index_type i); |
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| 53 | // |
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| 54 | // static void |
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| 55 | // delete_slice(Container& container, index_type from, index_type to); |
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| 56 | // |
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| 57 | // static size_t |
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| 58 | // size(Container& container); |
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| 59 | // |
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| 60 | // template <class T> |
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| 61 | // static bool |
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| 62 | // contains(Container& container, T const& val); |
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| 63 | // |
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| 64 | // static index_type |
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| 65 | // convert_index(Container& container, PyObject* i); |
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| 66 | // |
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| 67 | // static index_type |
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| 68 | // adjust_index(index_type current, index_type from, |
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| 69 | // index_type to, size_type len |
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| 70 | // ); |
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| 71 | // |
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| 72 | // Most of these policies are self explanatory. convert_index and |
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| 73 | // adjust_index, however, deserves some explanation. |
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| 74 | // |
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| 75 | // convert_index converts an Python index into a C++ index that the |
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| 76 | // container can handle. For instance, negative indexes in Python, by |
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| 77 | // convention, indexes from the right (e.g. C[-1] indexes the rightmost |
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| 78 | // element in C). convert_index should handle the necessary conversion |
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| 79 | // for the C++ container (e.g. convert -1 to C.size()-1). convert_index |
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| 80 | // should also be able to convert the type of the index (A dynamic Python |
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| 81 | // type) to the actual type that the C++ container expects. |
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| 82 | // |
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| 83 | // When a container expands or contracts, held indexes to its elements |
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| 84 | // must be adjusted to follow the movement of data. For instance, if |
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| 85 | // we erase 3 elements, starting from index 0 from a 5 element vector, |
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| 86 | // what used to be at index 4 will now be at index 1: |
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| 87 | // |
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| 88 | // [a][b][c][d][e] ---> [d][e] |
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| 89 | // ^ ^ |
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| 90 | // 4 1 |
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| 91 | // |
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| 92 | // adjust_index takes care of the adjustment. Given a current index, |
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| 93 | // the function should return the adjusted index when data in the |
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| 94 | // container at index from..to is replaced by *len* elements. |
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| 95 | // |
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| 96 | |
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| 97 | template < |
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| 98 | class Container |
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| 99 | , class DerivedPolicies |
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| 100 | , bool NoProxy = false |
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| 101 | , bool NoSlice = false |
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| 102 | , class Data = typename Container::value_type |
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| 103 | , class Index = typename Container::size_type |
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| 104 | , class Key = typename Container::value_type |
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| 105 | > |
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| 106 | class indexing_suite |
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| 107 | : public def_visitor< |
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| 108 | indexing_suite< |
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| 109 | Container |
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| 110 | , DerivedPolicies |
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| 111 | , NoProxy |
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| 112 | , NoSlice |
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| 113 | , Data |
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| 114 | , Index |
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| 115 | , Key |
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| 116 | > > |
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| 117 | { |
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| 118 | private: |
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| 119 | |
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| 120 | typedef mpl::or_< |
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| 121 | mpl::bool_<NoProxy> |
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| 122 | , mpl::not_<is_class<Data> > > |
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| 123 | no_proxy; |
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| 124 | |
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| 125 | typedef detail::container_element<Container, Index, DerivedPolicies> |
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| 126 | container_element_t; |
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| 127 | |
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| 128 | #if BOOST_WORKAROUND(BOOST_MSVC, == 1200) |
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| 129 | struct return_policy : return_internal_reference<> {}; |
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| 130 | #else |
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| 131 | typedef return_internal_reference<> return_policy; |
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| 132 | #endif |
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| 133 | |
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| 134 | typedef typename mpl::if_< |
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| 135 | no_proxy |
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| 136 | , iterator<Container> |
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| 137 | , iterator<Container, return_policy> >::type |
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| 138 | def_iterator; |
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| 139 | |
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| 140 | typedef typename mpl::if_< |
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| 141 | no_proxy |
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| 142 | , detail::no_proxy_helper< |
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| 143 | Container |
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| 144 | , DerivedPolicies |
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| 145 | , container_element_t |
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| 146 | , Index> |
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| 147 | , detail::proxy_helper< |
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| 148 | Container |
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| 149 | , DerivedPolicies |
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| 150 | , container_element_t |
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| 151 | , Index> >::type |
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| 152 | proxy_handler; |
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| 153 | |
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| 154 | typedef typename mpl::if_< |
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| 155 | mpl::bool_<NoSlice> |
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| 156 | , detail::no_slice_helper< |
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| 157 | Container |
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| 158 | , DerivedPolicies |
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| 159 | , proxy_handler |
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| 160 | , Data |
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| 161 | , Index> |
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| 162 | , detail::slice_helper< |
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| 163 | Container |
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| 164 | , DerivedPolicies |
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| 165 | , proxy_handler |
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| 166 | , Data |
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| 167 | , Index> >::type |
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| 168 | slice_handler; |
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| 169 | |
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| 170 | public: |
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| 171 | |
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| 172 | template <class Class> |
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| 173 | void visit(Class& cl) const |
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| 174 | { |
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| 175 | // Hook into the class_ generic visitation .def function |
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| 176 | proxy_handler::register_container_element(); |
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| 177 | |
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| 178 | cl |
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| 179 | .def("__len__", base_size) |
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| 180 | .def("__setitem__", &base_set_item) |
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| 181 | .def("__delitem__", &base_delete_item) |
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| 182 | .def("__getitem__", &base_get_item) |
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| 183 | .def("__contains__", &base_contains) |
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| 184 | .def("__iter__", def_iterator()) |
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| 185 | ; |
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| 186 | |
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| 187 | DerivedPolicies::extension_def(cl); |
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| 188 | } |
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| 189 | |
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| 190 | template <class Class> |
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| 191 | static void |
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| 192 | extension_def(Class& cl) |
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| 193 | { |
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| 194 | // default. |
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| 195 | // no more extensions |
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| 196 | } |
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| 197 | |
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| 198 | private: |
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| 199 | |
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| 200 | static object |
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| 201 | base_get_item(back_reference<Container&> container, PyObject* i) |
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| 202 | { |
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| 203 | if (PySlice_Check(i)) |
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| 204 | return slice_handler::base_get_slice( |
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| 205 | container.get(), reinterpret_cast<PySliceObject*>(i)); |
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| 206 | |
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| 207 | return proxy_handler::base_get_item_(container, i); |
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| 208 | } |
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| 209 | |
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| 210 | static void |
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| 211 | base_set_item(Container& container, PyObject* i, PyObject* v) |
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| 212 | { |
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| 213 | if (PySlice_Check(i)) |
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| 214 | { |
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| 215 | slice_handler::base_set_slice(container, |
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| 216 | reinterpret_cast<PySliceObject*>(i), v); |
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| 217 | } |
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| 218 | else |
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| 219 | { |
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| 220 | extract<Data&> elem(v); |
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| 221 | // try if elem is an exact Data |
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| 222 | if (elem.check()) |
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| 223 | { |
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| 224 | DerivedPolicies:: |
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| 225 | set_item(container, |
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| 226 | DerivedPolicies:: |
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| 227 | convert_index(container, i), elem()); |
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| 228 | } |
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| 229 | else |
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| 230 | { |
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| 231 | // try to convert elem to Data |
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| 232 | extract<Data> elem(v); |
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| 233 | if (elem.check()) |
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| 234 | { |
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| 235 | DerivedPolicies:: |
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| 236 | set_item(container, |
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| 237 | DerivedPolicies:: |
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| 238 | convert_index(container, i), elem()); |
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| 239 | } |
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| 240 | else |
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| 241 | { |
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| 242 | PyErr_SetString(PyExc_TypeError, "Invalid assignment"); |
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| 243 | throw_error_already_set(); |
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| 244 | } |
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| 245 | } |
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| 246 | } |
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| 247 | } |
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| 248 | |
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| 249 | static void |
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| 250 | base_delete_item(Container& container, PyObject* i) |
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| 251 | { |
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| 252 | if (PySlice_Check(i)) |
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| 253 | { |
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| 254 | slice_handler::base_delete_slice( |
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| 255 | container, reinterpret_cast<PySliceObject*>(i)); |
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| 256 | return; |
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| 257 | } |
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| 258 | |
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| 259 | Index index = DerivedPolicies::convert_index(container, i); |
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| 260 | proxy_handler::base_erase_index(container, index, mpl::bool_<NoSlice>()); |
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| 261 | DerivedPolicies::delete_item(container, index); |
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| 262 | } |
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| 263 | |
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| 264 | static size_t |
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| 265 | base_size(Container& container) |
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| 266 | { |
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| 267 | return DerivedPolicies::size(container); |
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| 268 | } |
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| 269 | |
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| 270 | static bool |
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| 271 | base_contains(Container& container, PyObject* key) |
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| 272 | { |
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| 273 | extract<Key const&> x(key); |
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| 274 | // try if key is an exact Key type |
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| 275 | if (x.check()) |
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| 276 | { |
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| 277 | return DerivedPolicies::contains(container, x()); |
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| 278 | } |
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| 279 | else |
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| 280 | { |
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| 281 | // try to convert key to Key type |
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| 282 | extract<Key> x(key); |
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| 283 | if (x.check()) |
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| 284 | return DerivedPolicies::contains(container, x()); |
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| 285 | else |
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| 286 | return false; |
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| 287 | } |
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| 288 | } |
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| 289 | }; |
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| 290 | |
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| 291 | }} // namespace boost::python |
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| 292 | |
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| 293 | #endif // INDEXING_SUITE_JDG20036_HPP |
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