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Diffstat (limited to 'ext/pybind11/tests/test_sequences_and_iterators.cpp')
| -rw-r--r-- | ext/pybind11/tests/test_sequences_and_iterators.cpp | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/ext/pybind11/tests/test_sequences_and_iterators.cpp b/ext/pybind11/tests/test_sequences_and_iterators.cpp new file mode 100644 index 000000000..323b4bf00 --- /dev/null +++ b/ext/pybind11/tests/test_sequences_and_iterators.cpp @@ -0,0 +1,275 @@ +/* + tests/test_sequences_and_iterators.cpp -- supporting Pythons' sequence protocol, iterators, + etc. + + Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch> + + All rights reserved. Use of this source code is governed by a + BSD-style license that can be found in the LICENSE file. +*/ + +#include "pybind11_tests.h" +#include "constructor_stats.h" +#include <pybind11/operators.h> +#include <pybind11/stl.h> + +class Sequence { +public: + Sequence(size_t size) : m_size(size) { + print_created(this, "of size", m_size); + m_data = new float[size]; + memset(m_data, 0, sizeof(float) * size); + } + + Sequence(const std::vector<float> &value) : m_size(value.size()) { + print_created(this, "of size", m_size, "from std::vector"); + m_data = new float[m_size]; + memcpy(m_data, &value[0], sizeof(float) * m_size); + } + + Sequence(const Sequence &s) : m_size(s.m_size) { + print_copy_created(this); + m_data = new float[m_size]; + memcpy(m_data, s.m_data, sizeof(float)*m_size); + } + + Sequence(Sequence &&s) : m_size(s.m_size), m_data(s.m_data) { + print_move_created(this); + s.m_size = 0; + s.m_data = nullptr; + } + + ~Sequence() { + print_destroyed(this); + delete[] m_data; + } + + Sequence &operator=(const Sequence &s) { + if (&s != this) { + delete[] m_data; + m_size = s.m_size; + m_data = new float[m_size]; + memcpy(m_data, s.m_data, sizeof(float)*m_size); + } + + print_copy_assigned(this); + + return *this; + } + + Sequence &operator=(Sequence &&s) { + if (&s != this) { + delete[] m_data; + m_size = s.m_size; + m_data = s.m_data; + s.m_size = 0; + s.m_data = nullptr; + } + + print_move_assigned(this); + + return *this; + } + + bool operator==(const Sequence &s) const { + if (m_size != s.size()) + return false; + for (size_t i=0; i<m_size; ++i) + if (m_data[i] != s[i]) + return false; + return true; + } + + bool operator!=(const Sequence &s) const { + return !operator==(s); + } + + float operator[](size_t index) const { + return m_data[index]; + } + + float &operator[](size_t index) { + return m_data[index]; + } + + bool contains(float v) const { + for (size_t i=0; i<m_size; ++i) + if (v == m_data[i]) + return true; + return false; + } + + Sequence reversed() const { + Sequence result(m_size); + for (size_t i=0; i<m_size; ++i) + result[m_size-i-1] = m_data[i]; + return result; + } + + size_t size() const { return m_size; } + + const float *begin() const { return m_data; } + const float *end() const { return m_data+m_size; } + +private: + size_t m_size; + float *m_data; +}; + +class IntPairs { +public: + IntPairs(std::vector<std::pair<int, int>> data) : data_(std::move(data)) {} + const std::pair<int, int>* begin() const { return data_.data(); } + +private: + std::vector<std::pair<int, int>> data_; +}; + +// Interface of a map-like object that isn't (directly) an unordered_map, but provides some basic +// map-like functionality. +class StringMap { +public: + StringMap() = default; + StringMap(std::unordered_map<std::string, std::string> init) + : map(std::move(init)) {} + + void set(std::string key, std::string val) { + map[key] = val; + } + + std::string get(std::string key) const { + return map.at(key); + } + + size_t size() const { + return map.size(); + } + +private: + std::unordered_map<std::string, std::string> map; + +public: + decltype(map.cbegin()) begin() const { return map.cbegin(); } + decltype(map.cend()) end() const { return map.cend(); } +}; + +template<typename T> +class NonZeroIterator { + const T* ptr_; +public: + NonZeroIterator(const T* ptr) : ptr_(ptr) {} + const T& operator*() const { return *ptr_; } + NonZeroIterator& operator++() { ++ptr_; return *this; } +}; + +class NonZeroSentinel {}; + +template<typename A, typename B> +bool operator==(const NonZeroIterator<std::pair<A, B>>& it, const NonZeroSentinel&) { + return !(*it).first || !(*it).second; +} + +test_initializer sequences_and_iterators([](py::module &m) { + + py::class_<Sequence> seq(m, "Sequence"); + + seq.def(py::init<size_t>()) + .def(py::init<const std::vector<float>&>()) + /// Bare bones interface + .def("__getitem__", [](const Sequence &s, size_t i) { + if (i >= s.size()) + throw py::index_error(); + return s[i]; + }) + .def("__setitem__", [](Sequence &s, size_t i, float v) { + if (i >= s.size()) + throw py::index_error(); + s[i] = v; + }) + .def("__len__", &Sequence::size) + /// Optional sequence protocol operations + .def("__iter__", [](const Sequence &s) { return py::make_iterator(s.begin(), s.end()); }, + py::keep_alive<0, 1>() /* Essential: keep object alive while iterator exists */) + .def("__contains__", [](const Sequence &s, float v) { return s.contains(v); }) + .def("__reversed__", [](const Sequence &s) -> Sequence { return s.reversed(); }) + /// Slicing protocol (optional) + .def("__getitem__", [](const Sequence &s, py::slice slice) -> Sequence* { + size_t start, stop, step, slicelength; + if (!slice.compute(s.size(), &start, &stop, &step, &slicelength)) + throw py::error_already_set(); + Sequence *seq = new Sequence(slicelength); + for (size_t i=0; i<slicelength; ++i) { + (*seq)[i] = s[start]; start += step; + } + return seq; + }) + .def("__setitem__", [](Sequence &s, py::slice slice, const Sequence &value) { + size_t start, stop, step, slicelength; + if (!slice.compute(s.size(), &start, &stop, &step, &slicelength)) + throw py::error_already_set(); + if (slicelength != value.size()) + throw std::runtime_error("Left and right hand size of slice assignment have different sizes!"); + for (size_t i=0; i<slicelength; ++i) { + s[start] = value[i]; start += step; + } + }) + /// Comparisons + .def(py::self == py::self) + .def(py::self != py::self); + // Could also define py::self + py::self for concatenation, etc. + + py::class_<StringMap> map(m, "StringMap"); + + map .def(py::init<>()) + .def(py::init<std::unordered_map<std::string, std::string>>()) + .def("__getitem__", [](const StringMap &map, std::string key) { + try { return map.get(key); } + catch (const std::out_of_range&) { + throw py::key_error("key '" + key + "' does not exist"); + } + }) + .def("__setitem__", &StringMap::set) + .def("__len__", &StringMap::size) + .def("__iter__", [](const StringMap &map) { return py::make_key_iterator(map.begin(), map.end()); }, + py::keep_alive<0, 1>()) + .def("items", [](const StringMap &map) { return py::make_iterator(map.begin(), map.end()); }, + py::keep_alive<0, 1>()) + ; + + py::class_<IntPairs>(m, "IntPairs") + .def(py::init<std::vector<std::pair<int, int>>>()) + .def("nonzero", [](const IntPairs& s) { + return py::make_iterator(NonZeroIterator<std::pair<int, int>>(s.begin()), NonZeroSentinel()); + }, py::keep_alive<0, 1>()) + .def("nonzero_keys", [](const IntPairs& s) { + return py::make_key_iterator(NonZeroIterator<std::pair<int, int>>(s.begin()), NonZeroSentinel()); + }, py::keep_alive<0, 1>()); + + +#if 0 + // Obsolete: special data structure for exposing custom iterator types to python + // kept here for illustrative purposes because there might be some use cases which + // are not covered by the much simpler py::make_iterator + + struct PySequenceIterator { + PySequenceIterator(const Sequence &seq, py::object ref) : seq(seq), ref(ref) { } + + float next() { + if (index == seq.size()) + throw py::stop_iteration(); + return seq[index++]; + } + + const Sequence &seq; + py::object ref; // keep a reference + size_t index = 0; + }; + + py::class_<PySequenceIterator>(seq, "Iterator") + .def("__iter__", [](PySequenceIterator &it) -> PySequenceIterator& { return it; }) + .def("__next__", &PySequenceIterator::next); + + On the actual Sequence object, the iterator would be constructed as follows: + .def("__iter__", [](py::object s) { return PySequenceIterator(s.cast<const Sequence &>(), s); }) +#endif +}); |