You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

275 lines
8.6 KiB

/*
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
});