forked from xtensor-stack/xtensor-python
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathpyarray_backstrides.hpp
More file actions
378 lines (304 loc) · 10.4 KB
/
pyarray_backstrides.hpp
File metadata and controls
378 lines (304 loc) · 10.4 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
/***************************************************************************
* Copyright (c) Wolf Vollprecht, Johan Mabille and Sylvain Corlay *
* Copyright (c) QuantStack *
* *
* Distributed under the terms of the BSD 3-Clause License. *
* *
* The full license is in the file LICENSE, distributed with this software. *
****************************************************************************/
#ifndef PY_ARRAY_BACKSTRIDES_HPP
#define PY_ARRAY_BACKSTRIDES_HPP
#include <cstddef>
#include <iterator>
namespace xt
{
/**************************
* pybackstrides_iterator *
**************************/
template <class B>
class pybackstrides_iterator
{
public:
using self_type = pybackstrides_iterator<B>;
using value_type = typename B::value_type;
using pointer = const value_type*;
using reference = value_type;
using difference_type = std::ptrdiff_t;
using iterator_category = std::random_access_iterator_tag;
pybackstrides_iterator(const B* b, std::size_t offset);
reference operator*() const;
pointer operator->() const;
reference operator[](difference_type n) const;
self_type& operator++();
self_type& operator--();
self_type operator++(int);
self_type operator--(int);
self_type& operator+=(difference_type n);
self_type& operator-=(difference_type n);
self_type operator+(difference_type n) const;
self_type operator-(difference_type n) const;
self_type operator-(const self_type& rhs) const;
std::size_t offset() const;
private:
const B* p_b;
std::size_t m_offset;
};
template <class B>
inline bool operator==(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs);
template <class B>
inline bool operator!=(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs);
template <class B>
inline bool operator<(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs);
template <class B>
inline bool operator<=(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs);
template <class B>
inline bool operator>(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs);
template <class B>
inline bool operator>=(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs);
/***********************
* pyarray_backstrides *
***********************/
template <class A>
class pyarray_backstrides
{
public:
using self_type = pyarray_backstrides<A>;
using array_type = A;
using value_type = typename array_type::size_type;
using const_reference = value_type;
using reference = const_reference;
using const_pointer = const value_type*;
using pointer = const_pointer;
using size_type = typename array_type::size_type;
using difference_type = typename array_type::difference_type;
using const_iterator = pybackstrides_iterator<self_type>;
using iterator = const_iterator;
using reverse_iterator = std::reverse_iterator<iterator>;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
pyarray_backstrides() = default;
pyarray_backstrides(const array_type& a);
bool empty() const;
size_type size() const;
value_type operator[](size_type i) const;
const_reference front() const;
const_reference back() const;
const_iterator begin() const;
const_iterator end() const;
const_iterator cbegin() const;
const_iterator cend() const;
const_reverse_iterator rbegin() const;
const_reverse_iterator rend() const;
const_reverse_iterator crbegin() const;
const_reverse_iterator crend() const;
private:
const array_type* p_a;
};
/*****************************************
* pybackstrides_iterator implementation *
*****************************************/
template <class B>
inline pybackstrides_iterator<B>::pybackstrides_iterator(const B* b, std::size_t offset)
: p_b(b), m_offset(offset)
{
}
template <class B>
inline auto pybackstrides_iterator<B>::operator*() const -> reference
{
return p_b->operator[](m_offset);
}
template <class B>
inline auto pybackstrides_iterator<B>::operator->() const -> pointer
{
// Returning the address of a temporary
value_type res = p_b->operator[](m_offset);
return &res;
}
template <class B>
inline auto pybackstrides_iterator<B>::operator[](difference_type n) const -> reference
{
return p_b->operator[](m_offset + n);
}
template <class B>
inline auto pybackstrides_iterator<B>::operator++() -> self_type&
{
++m_offset;
return *this;
}
template <class B>
inline auto pybackstrides_iterator<B>::operator--() -> self_type&
{
--m_offset;
return *this;
}
template <class B>
inline auto pybackstrides_iterator<B>::operator++(int )-> self_type
{
self_type tmp(*this);
++m_offset;
return tmp;
}
template <class B>
inline auto pybackstrides_iterator<B>::operator--(int) -> self_type
{
self_type tmp(*this);
--m_offset;
return tmp;
}
template <class B>
inline auto pybackstrides_iterator<B>::operator+=(difference_type n) -> self_type&
{
m_offset += n;
return *this;
}
template <class B>
inline auto pybackstrides_iterator<B>::operator-=(difference_type n) -> self_type&
{
m_offset -= n;
return *this;
}
template <class B>
inline auto pybackstrides_iterator<B>::operator+(difference_type n) const -> self_type
{
return self_type(p_b, m_offset + n);
}
template <class B>
inline auto pybackstrides_iterator<B>::operator-(difference_type n) const -> self_type
{
return self_type(p_b, m_offset - n);
}
template <class B>
inline auto pybackstrides_iterator<B>::operator-(const self_type& rhs) const -> self_type
{
self_type tmp(*this);
tmp -= (m_offset - rhs.m_offset);
return tmp;
}
template <class B>
inline std::size_t pybackstrides_iterator<B>::offset() const
{
return m_offset;
}
template <class B>
inline bool operator==(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs)
{
return lhs.offset() == rhs.offset();
}
template <class B>
inline bool operator!=(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs)
{
return !(lhs == rhs);
}
template <class B>
inline bool operator<(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs)
{
return lhs.offset() < rhs.offset();
}
template <class B>
inline bool operator<=(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs)
{
return (lhs < rhs) || (lhs == rhs);
}
template <class B>
inline bool operator>(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs)
{
return !(lhs <= rhs);
}
template <class B>
inline bool operator>=(const pybackstrides_iterator<B>& lhs,
const pybackstrides_iterator<B>& rhs)
{
return !(lhs < rhs);
}
/**************************************
* pyarray_backstrides implementation *
**************************************/
template <class A>
inline pyarray_backstrides<A>::pyarray_backstrides(const array_type& a)
: p_a(&a)
{
}
template <class A>
inline bool pyarray_backstrides<A>::empty() const
{
return p_a->dimension() == 0;
}
template <class A>
inline auto pyarray_backstrides<A>::size() const -> size_type
{
return p_a->dimension();
}
template <class A>
inline auto pyarray_backstrides<A>::operator[](size_type i) const -> value_type
{
value_type sh = p_a->shape()[i];
value_type res = sh == 1 ? 0 : (sh - 1) * p_a->strides()[i];
return res;
}
template <class A>
inline auto pyarray_backstrides<A>::front() const -> const_reference
{
value_type sh = p_a->shape()[0];
value_type res = sh == 1 ? 0 : (sh - 1) * p_a->strides()[0];
return res;
}
template <class A>
inline auto pyarray_backstrides<A>::back() const -> const_reference
{
auto index = p_a->size() - 1;
value_type sh = p_a->shape()[index];
value_type res = sh == 1 ? 0 : (sh - 1) * p_a->strides()[index];
return res;
}
template <class A>
inline auto pyarray_backstrides<A>::begin() const -> const_iterator
{
return cbegin();
}
template <class A>
inline auto pyarray_backstrides<A>::end() const -> const_iterator
{
return cend();
}
template <class A>
inline auto pyarray_backstrides<A>::cbegin() const -> const_iterator
{
return const_iterator(this, 0);
}
template <class A>
inline auto pyarray_backstrides<A>::cend() const -> const_iterator
{
return const_iterator(this, size());
}
template <class A>
inline auto pyarray_backstrides<A>::rbegin() const -> const_reverse_iterator
{
return crbegin();
}
template <class A>
inline auto pyarray_backstrides<A>::rend() const -> const_reverse_iterator
{
return crend();
}
template <class A>
inline auto pyarray_backstrides<A>::crbegin() const -> const_reverse_iterator
{
return const_reverse_iterator(end());
}
template <class A>
inline auto pyarray_backstrides<A>::crend() const -> const_reverse_iterator
{
return const_reverse_iterator(begin());
}
}
#endif