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1// -*- C++ -*-2//===----------------------------------------------------------------------===//3//4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.5// See https://llvm.org/LICENSE.txt for license information.6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP___RANGES_SPLIT_VIEW_H11#define _LIBCPP___RANGES_SPLIT_VIEW_H12 13#include <__algorithm/ranges_search.h>14#include <__concepts/constructible.h>15#include <__config>16#include <__functional/bind_back.h>17#include <__functional/ranges_operations.h>18#include <__iterator/indirectly_comparable.h>19#include <__iterator/iterator_traits.h>20#include <__memory/addressof.h>21#include <__ranges/access.h>22#include <__ranges/all.h>23#include <__ranges/concepts.h>24#include <__ranges/empty.h>25#include <__ranges/non_propagating_cache.h>26#include <__ranges/range_adaptor.h>27#include <__ranges/single_view.h>28#include <__ranges/subrange.h>29#include <__ranges/view_interface.h>30#include <__type_traits/decay.h>31#include <__type_traits/is_nothrow_constructible.h>32#include <__utility/forward.h>33#include <__utility/move.h>34 35#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)36# pragma GCC system_header37#endif38 39_LIBCPP_PUSH_MACROS40#include <__undef_macros>41 42_LIBCPP_BEGIN_NAMESPACE_STD43 44#if _LIBCPP_STD_VER >= 2045 46namespace ranges {47 48template <forward_range _View, forward_range _Pattern>49 requires view<_View> && view<_Pattern> &&50 indirectly_comparable<iterator_t<_View>, iterator_t<_Pattern>, ranges::equal_to>51class split_view : public view_interface<split_view<_View, _Pattern>> {52private:53 _LIBCPP_NO_UNIQUE_ADDRESS _View __base_ = _View();54 _LIBCPP_NO_UNIQUE_ADDRESS _Pattern __pattern_ = _Pattern();55 using _Cache _LIBCPP_NODEBUG = __non_propagating_cache<subrange<iterator_t<_View>>>;56 _Cache __cached_begin_ = _Cache();57 58 template <class, class>59 friend struct __iterator;60 61 template <class, class>62 friend struct __sentinel;63 64 struct __iterator;65 struct __sentinel;66 67 _LIBCPP_HIDE_FROM_ABI constexpr subrange<iterator_t<_View>> __find_next(iterator_t<_View> __it) {68 auto [__begin, __end] = ranges::search(subrange(__it, ranges::end(__base_)), __pattern_);69 if (__begin != ranges::end(__base_) && ranges::empty(__pattern_)) {70 ++__begin;71 ++__end;72 }73 return {__begin, __end};74 }75 76public:77 _LIBCPP_HIDE_FROM_ABI split_view()78 requires default_initializable<_View> && default_initializable<_Pattern>79 = default;80 81 _LIBCPP_HIDE_FROM_ABI constexpr _LIBCPP_EXPLICIT_SINCE_CXX23 split_view(_View __base, _Pattern __pattern)82 : __base_(std::move(__base)), __pattern_(std::move((__pattern))) {}83 84 template <forward_range _Range>85 requires constructible_from<_View, views::all_t<_Range>> &&86 constructible_from<_Pattern, single_view<range_value_t<_Range>>>87 _LIBCPP_HIDE_FROM_ABI constexpr _LIBCPP_EXPLICIT_SINCE_CXX2388 split_view(_Range&& __range, range_value_t<_Range> __elem)89 : __base_(views::all(std::forward<_Range>(__range))), __pattern_(views::single(std::move(__elem))) {}90 91 _LIBCPP_HIDE_FROM_ABI constexpr _View base() const&92 requires copy_constructible<_View>93 {94 return __base_;95 }96 97 _LIBCPP_HIDE_FROM_ABI constexpr _View base() && { return std::move(__base_); }98 99 _LIBCPP_HIDE_FROM_ABI constexpr __iterator begin() {100 if (!__cached_begin_.__has_value()) {101 __cached_begin_.__emplace(__find_next(ranges::begin(__base_)));102 }103 return {*this, ranges::begin(__base_), *__cached_begin_};104 }105 106 _LIBCPP_HIDE_FROM_ABI constexpr auto end() {107 if constexpr (common_range<_View>) {108 return __iterator{*this, ranges::end(__base_), {}};109 } else {110 return __sentinel{*this};111 }112 }113};114 115template <class _Range, class _Pattern>116split_view(_Range&&, _Pattern&&) -> split_view<views::all_t<_Range>, views::all_t<_Pattern>>;117 118template <forward_range _Range>119split_view(_Range&&, range_value_t<_Range>) -> split_view<views::all_t<_Range>, single_view<range_value_t<_Range>>>;120 121template <forward_range _View, forward_range _Pattern>122 requires view<_View> && view<_Pattern> &&123 indirectly_comparable<iterator_t<_View>, iterator_t<_Pattern>, ranges::equal_to>124struct split_view<_View, _Pattern>::__iterator {125private:126 split_view* __parent_ = nullptr;127 _LIBCPP_NO_UNIQUE_ADDRESS iterator_t<_View> __cur_ = iterator_t<_View>();128 _LIBCPP_NO_UNIQUE_ADDRESS subrange<iterator_t<_View>> __next_ = subrange<iterator_t<_View>>();129 bool __trailing_empty_ = false;130 131 friend struct __sentinel;132 133public:134 using iterator_concept = forward_iterator_tag;135 using iterator_category = input_iterator_tag;136 using value_type = subrange<iterator_t<_View>>;137 using difference_type = range_difference_t<_View>;138 139 _LIBCPP_HIDE_FROM_ABI __iterator() = default;140 141 _LIBCPP_HIDE_FROM_ABI constexpr __iterator(142 split_view<_View, _Pattern>& __parent, iterator_t<_View> __current, subrange<iterator_t<_View>> __next)143 : __parent_(std::addressof(__parent)), __cur_(std::move(__current)), __next_(std::move(__next)) {}144 145 _LIBCPP_HIDE_FROM_ABI constexpr iterator_t<_View> base() const { return __cur_; }146 147 _LIBCPP_HIDE_FROM_ABI constexpr value_type operator*() const { return {__cur_, __next_.begin()}; }148 149 _LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator++() {150 __cur_ = __next_.begin();151 if (__cur_ != ranges::end(__parent_->__base_)) {152 __cur_ = __next_.end();153 if (__cur_ == ranges::end(__parent_->__base_)) {154 __trailing_empty_ = true;155 __next_ = {__cur_, __cur_};156 } else {157 __next_ = __parent_->__find_next(__cur_);158 }159 } else {160 __trailing_empty_ = false;161 }162 return *this;163 }164 165 _LIBCPP_HIDE_FROM_ABI constexpr __iterator operator++(int) {166 auto __tmp = *this;167 ++*this;168 return __tmp;169 }170 171 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __iterator& __x, const __iterator& __y) {172 return __x.__cur_ == __y.__cur_ && __x.__trailing_empty_ == __y.__trailing_empty_;173 }174};175 176template <forward_range _View, forward_range _Pattern>177 requires view<_View> && view<_Pattern> &&178 indirectly_comparable<iterator_t<_View>, iterator_t<_Pattern>, ranges::equal_to>179struct split_view<_View, _Pattern>::__sentinel {180private:181 _LIBCPP_NO_UNIQUE_ADDRESS sentinel_t<_View> __end_ = sentinel_t<_View>();182 183 _LIBCPP_HIDE_FROM_ABI static constexpr bool __equals(const __iterator& __x, const __sentinel& __y) {184 return __x.__cur_ == __y.__end_ && !__x.__trailing_empty_;185 }186 187public:188 _LIBCPP_HIDE_FROM_ABI __sentinel() = default;189 190 _LIBCPP_HIDE_FROM_ABI constexpr explicit __sentinel(split_view<_View, _Pattern>& __parent)191 : __end_(ranges::end(__parent.__base_)) {}192 193 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __iterator& __x, const __sentinel& __y) {194 return __equals(__x, __y);195 }196};197 198namespace views {199namespace __split_view {200struct __fn {201 // clang-format off202 template <class _Range, class _Pattern>203 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI204 constexpr auto operator()(_Range&& __range, _Pattern&& __pattern) const205 noexcept(noexcept(split_view(std::forward<_Range>(__range), std::forward<_Pattern>(__pattern))))206 -> decltype( split_view(std::forward<_Range>(__range), std::forward<_Pattern>(__pattern)))207 { return split_view(std::forward<_Range>(__range), std::forward<_Pattern>(__pattern)); }208 // clang-format on209 210 template <class _Pattern>211 requires constructible_from<decay_t<_Pattern>, _Pattern>212 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Pattern&& __pattern) const213 noexcept(is_nothrow_constructible_v<decay_t<_Pattern>, _Pattern>) {214 return __pipeable(std::__bind_back(*this, std::forward<_Pattern>(__pattern)));215 }216};217} // namespace __split_view218 219inline namespace __cpo {220inline constexpr auto split = __split_view::__fn{};221} // namespace __cpo222} // namespace views223 224} // namespace ranges225 226#endif // _LIBCPP_STD_VER >= 20227 228_LIBCPP_END_NAMESPACE_STD229 230_LIBCPP_POP_MACROS231 232#endif // _LIBCPP___RANGES_SPLIT_VIEW_H233