about summary refs log blame commit diff
path: root/third_party/immer/immer/vector.hpp
blob: 4f1a148ccd008f483d0fad4b91f392ad6f4c7492 (plain) (tree)
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
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412



























































































































































































































































































































































































































                                                                              
//
// immer: immutable data structures for C++
// Copyright (C) 2016, 2017, 2018 Juan Pedro Bolivar Puente
//
// This software is distributed under the Boost Software License, Version 1.0.
// See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt
//

#pragma once

#include <immer/detail/rbts/rbtree.hpp>
#include <immer/detail/rbts/rbtree_iterator.hpp>
#include <immer/memory_policy.hpp>

#if IMMER_DEBUG_PRINT
#include <immer/flex_vector.hpp>
#endif

namespace immer {

template <typename T,
          typename MemoryPolicy,
          detail::rbts::bits_t B,
          detail::rbts::bits_t BL>
class flex_vector;

template <typename T,
          typename MemoryPolicy,
          detail::rbts::bits_t B,
          detail::rbts::bits_t BL>
class vector_transient;

/*!
 * Immutable sequential container supporting both random access and
 * structural sharing.
 *
 * @tparam T The type of the values to be stored in the container.
 * @tparam MemoryPolicy Memory management policy. See @ref
 *         memory_policy.
 *
 * @rst
 *
 * This cotainer provides a good trade-off between cache locality,
 * random access, update performance and structural sharing.  It does
 * so by storing the data in contiguous chunks of :math:`2^{BL}`
 * elements.  By default, when ``sizeof(T) == sizeof(void*)`` then
 * :math:`B=BL=5`, such that data would be stored in contiguous
 * chunks of :math:`32` elements.
 *
 * You may learn more about the meaning and implications of ``B`` and
 * ``BL`` parameters in the :doc:`implementation` section.
 *
 * .. note:: In several methods we say that their complexity is
 *    *effectively* :math:`O(...)`. Do not confuse this with the word
 *    *amortized*, which has a very different meaning.  In this
 *    context, *effective* means that while the
 *    mathematically rigurous
 *    complexity might be higher, for all practical matters the
 *    provided complexity is more useful to think about the actual
 *    cost of the operation.
 *
 * **Example**
 *   .. literalinclude:: ../example/vector/intro.cpp
 *      :language: c++
 *      :start-after: intro/start
 *      :end-before:  intro/end
 *
 * @endrst
 */
template <typename T,
          typename MemoryPolicy  = default_memory_policy,
          detail::rbts::bits_t B = default_bits,
          detail::rbts::bits_t BL =
              detail::rbts::derive_bits_leaf<T, MemoryPolicy, B>>
class vector
{
    using impl_t = detail::rbts::rbtree<T, MemoryPolicy, B, BL>;
    using flex_t = flex_vector<T, MemoryPolicy, B, BL>;

    using move_t =
        std::integral_constant<bool, MemoryPolicy::use_transient_rvalues>;

public:
    static constexpr auto bits      = B;
    static constexpr auto bits_leaf = BL;
    using memory_policy             = MemoryPolicy;

    using value_type      = T;
    using reference       = const T&;
    using size_type       = detail::rbts::size_t;
    using difference_type = std::ptrdiff_t;
    using const_reference = const T&;

    using iterator = detail::rbts::rbtree_iterator<T, MemoryPolicy, B, BL>;
    using const_iterator   = iterator;
    using reverse_iterator = std::reverse_iterator<iterator>;

    using transient_type = vector_transient<T, MemoryPolicy, B, BL>;

    /*!
     * Default constructor.  It creates a vector of `size() == 0`.  It
     * does not allocate memory and its complexity is @f$ O(1) @f$.
     */
    vector() = default;

    /*!
     * Constructs a vector containing the elements in `values`.
     */
    vector(std::initializer_list<T> values)
        : impl_{impl_t::from_initializer_list(values)}
    {}

    /*!
     * Constructs a vector containing the elements in the range
     * defined by the input iterator `first` and range sentinel `last`.
     */
    template <typename Iter,
              typename Sent,
              std::enable_if_t<detail::compatible_sentinel_v<Iter, Sent>,
                               bool> = true>
    vector(Iter first, Sent last)
        : impl_{impl_t::from_range(first, last)}
    {}

    /*!
     * Constructs a vector containing the element `val` repeated `n`
     * times.
     */
    vector(size_type n, T v = {})
        : impl_{impl_t::from_fill(n, v)}
    {}

    /*!
     * Returns an iterator pointing at the first element of the
     * collection. It does not allocate memory and its complexity is
     * @f$ O(1) @f$.
     */
    IMMER_NODISCARD iterator begin() const { return {impl_}; }

    /*!
     * Returns an iterator pointing just after the last element of the
     * collection. It does not allocate and its complexity is @f$ O(1) @f$.
     */
    IMMER_NODISCARD iterator end() const
    {
        return {impl_, typename iterator::end_t{}};
    }

    /*!
     * Returns an iterator that traverses the collection backwards,
     * pointing at the first element of the reversed collection. It
     * does not allocate memory and its complexity is @f$ O(1) @f$.
     */
    IMMER_NODISCARD reverse_iterator rbegin() const
    {
        return reverse_iterator{end()};
    }

    /*!
     * Returns an iterator that traverses the collection backwards,
     * pointing after the last element of the reversed collection. It
     * does not allocate memory and its complexity is @f$ O(1) @f$.
     */
    IMMER_NODISCARD reverse_iterator rend() const
    {
        return reverse_iterator{begin()};
    }

    /*!
     * Returns the number of elements in the container.  It does
     * not allocate memory and its complexity is @f$ O(1) @f$.
     */
    IMMER_NODISCARD size_type size() const { return impl_.size; }

    /*!
     * Returns `true` if there are no elements in the container.  It
     * does not allocate memory and its complexity is @f$ O(1) @f$.
     */
    IMMER_NODISCARD bool empty() const { return impl_.size == 0; }

    /*!
     * Access the last element.
     */
    IMMER_NODISCARD const T& back() const { return impl_.back(); }

    /*!
     * Access the first element.
     */
    IMMER_NODISCARD const T& front() const { return impl_.front(); }

    /*!
     * Returns a `const` reference to the element at position `index`.
     * It is undefined when @f$ 0 index \geq size() @f$.  It does not
     * allocate memory and its complexity is *effectively* @f$ O(1)
     * @f$.
     */
    IMMER_NODISCARD reference operator[](size_type index) const
    {
        return impl_.get(index);
    }

    /*!
     * Returns a `const` reference to the element at position
     * `index`. It throws an `std::out_of_range` exception when @f$
     * index \geq size() @f$.  It does not allocate memory and its
     * complexity is *effectively* @f$ O(1) @f$.
     */
    reference at(size_type index) const { return impl_.get_check(index); }

    /*!
     * Returns whether the vectors are equal.
     */
    IMMER_NODISCARD bool operator==(const vector& other) const
    {
        return impl_.equals(other.impl_);
    }
    IMMER_NODISCARD bool operator!=(const vector& other) const
    {
        return !(*this == other);
    }

    /*!
     * Returns a vector with `value` inserted at the end.  It may
     * allocate memory and its complexity is *effectively* @f$ O(1) @f$.
     *
     * @rst
     *
     * **Example**
     *   .. literalinclude:: ../example/vector/vector.cpp
     *      :language: c++
     *      :dedent: 8
     *      :start-after: push-back/start
     *      :end-before:  push-back/end
     *
     * @endrst
     */
    IMMER_NODISCARD vector push_back(value_type value) const&
    {
        return impl_.push_back(std::move(value));
    }

    IMMER_NODISCARD decltype(auto) push_back(value_type value) &&
    {
        return push_back_move(move_t{}, std::move(value));
    }

    /*!
     * Returns a vector containing value `value` at position `idx`.
     * Undefined for `index >= size()`.
     * It may allocate memory and its complexity is
     * *effectively* @f$ O(1) @f$.
     *
     * @rst
     *
     * **Example**
     *   .. literalinclude:: ../example/vector/vector.cpp
     *      :language: c++
     *      :dedent: 8
     *      :start-after: set/start
     *      :end-before:  set/end
     *
     * @endrst
     */
    IMMER_NODISCARD vector set(size_type index, value_type value) const&
    {
        return impl_.assoc(index, std::move(value));
    }

    IMMER_NODISCARD decltype(auto) set(size_type index, value_type value) &&
    {
        return set_move(move_t{}, index, std::move(value));
    }

    /*!
     * Returns a vector containing the result of the expression
     * `fn((*this)[idx])` at position `idx`.
     * Undefined for `0 >= size()`.
     * It may allocate memory and its complexity is
     * *effectively* @f$ O(1) @f$.
     *
     * @rst
     *
     * **Example**
     *   .. literalinclude:: ../example/vector/vector.cpp
     *      :language: c++
     *      :dedent: 8
     *      :start-after: update/start
     *      :end-before:  update/end
     *
     * @endrst
     */
    template <typename FnT>
    IMMER_NODISCARD vector update(size_type index, FnT&& fn) const&
    {
        return impl_.update(index, std::forward<FnT>(fn));
    }

    template <typename FnT>
    IMMER_NODISCARD decltype(auto) update(size_type index, FnT&& fn) &&
    {
        return update_move(move_t{}, index, std::forward<FnT>(fn));
    }

    /*!
     * Returns a vector containing only the first `min(elems, size())`
     * elements. It may allocate memory and its complexity is
     * *effectively* @f$ O(1) @f$.
     *
     * @rst
     *
     * **Example**
     *   .. literalinclude:: ../example/vector/vector.cpp
     *      :language: c++
     *      :dedent: 8
     *      :start-after: take/start
     *      :end-before:  take/end
     *
     * @endrst
     */
    IMMER_NODISCARD vector take(size_type elems) const&
    {
        return impl_.take(elems);
    }

    IMMER_NODISCARD decltype(auto) take(size_type elems) &&
    {
        return take_move(move_t{}, elems);
    }

    /*!
     * Returns an @a transient form of this container, an
     * `immer::vector_transient`.
     */
    IMMER_NODISCARD transient_type transient() const&
    {
        return transient_type{impl_};
    }
    IMMER_NODISCARD transient_type transient() &&
    {
        return transient_type{std::move(impl_)};
    }

    // Semi-private
    const impl_t& impl() const { return impl_; }

#if IMMER_DEBUG_PRINT
    void debug_print(std::ostream& out = std::cerr) const
    {
        flex_t{*this}.debug_print(out);
    }
#endif

private:
    friend flex_t;
    friend transient_type;

    vector(impl_t impl)
        : impl_(std::move(impl))
    {
#if IMMER_DEBUG_PRINT
        // force the compiler to generate debug_print, so we can call
        // it from a debugger
        [](volatile auto) {}(&vector::debug_print);
#endif
    }

    vector&& push_back_move(std::true_type, value_type value)
    {
        impl_.push_back_mut({}, std::move(value));
        return std::move(*this);
    }
    vector push_back_move(std::false_type, value_type value)
    {
        return impl_.push_back(std::move(value));
    }

    vector&& set_move(std::true_type, size_type index, value_type value)
    {
        impl_.assoc_mut({}, index, std::move(value));
        return std::move(*this);
    }
    vector set_move(std::false_type, size_type index, value_type value)
    {
        return impl_.assoc(index, std::move(value));
    }

    template <typename Fn>
    vector&& update_move(std::true_type, size_type index, Fn&& fn)
    {
        impl_.update_mut({}, index, std::forward<Fn>(fn));
        return std::move(*this);
    }
    template <typename Fn>
    vector update_move(std::false_type, size_type index, Fn&& fn)
    {
        return impl_.update(index, std::forward<Fn>(fn));
    }

    vector&& take_move(std::true_type, size_type elems)
    {
        impl_.take_mut({}, elems);
        return std::move(*this);
    }
    vector take_move(std::false_type, size_type elems)
    {
        return impl_.take(elems);
    }

    impl_t impl_ = impl_t::empty();
};

} // namespace immer