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// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___RANGES_SPLIT_VIEW_H
#define _LIBCPP___RANGES_SPLIT_VIEW_H
#include <__algorithm/ranges_search.h>
#include <__concepts/constructible.h>
#include <__config>
#include <__functional/bind_back.h>
#include <__functional/ranges_operations.h>
#include <__iterator/indirectly_comparable.h>
#include <__iterator/iterator_traits.h>
#include <__memory/addressof.h>
#include <__ranges/access.h>
#include <__ranges/all.h>
#include <__ranges/concepts.h>
#include <__ranges/empty.h>
#include <__ranges/non_propagating_cache.h>
#include <__ranges/range_adaptor.h>
#include <__ranges/single_view.h>
#include <__ranges/subrange.h>
#include <__ranges/view_interface.h>
#include <__type_traits/decay.h>
#include <__type_traits/is_nothrow_constructible.h>
#include <__utility/forward.h>
#include <__utility/move.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 20
namespace ranges {
template <forward_range _View, forward_range _Pattern>
requires view<_View> && view<_Pattern> &&
indirectly_comparable<iterator_t<_View>, iterator_t<_Pattern>, ranges::equal_to>
class split_view : public view_interface<split_view<_View, _Pattern>> {
private:
_LIBCPP_NO_UNIQUE_ADDRESS _View __base_ = _View();
_LIBCPP_NO_UNIQUE_ADDRESS _Pattern __pattern_ = _Pattern();
using _Cache = __non_propagating_cache<subrange<iterator_t<_View>>>;
_Cache __cached_begin_ = _Cache();
template <class, class>
friend struct __iterator;
template <class, class>
friend struct __sentinel;
struct __iterator;
struct __sentinel;
_LIBCPP_HIDE_FROM_ABI constexpr subrange<iterator_t<_View>> __find_next(iterator_t<_View> __it) {
auto [__begin, __end] = ranges::search(subrange(__it, ranges::end(__base_)), __pattern_);
if (__begin != ranges::end(__base_) && ranges::empty(__pattern_)) {
++__begin;
++__end;
}
return {__begin, __end};
}
public:
_LIBCPP_HIDE_FROM_ABI split_view()
requires default_initializable<_View> && default_initializable<_Pattern>
= default;
_LIBCPP_HIDE_FROM_ABI constexpr _LIBCPP_EXPLICIT_SINCE_CXX23 split_view(_View __base, _Pattern __pattern)
: __base_(std::move(__base)), __pattern_(std::move((__pattern))) {}
template <forward_range _Range>
requires constructible_from<_View, views::all_t<_Range>> &&
constructible_from<_Pattern, single_view<range_value_t<_Range>>>
_LIBCPP_HIDE_FROM_ABI constexpr _LIBCPP_EXPLICIT_SINCE_CXX23
split_view(_Range&& __range, range_value_t<_Range> __elem)
: __base_(views::all(std::forward<_Range>(__range))), __pattern_(views::single(std::move(__elem))) {}
_LIBCPP_HIDE_FROM_ABI constexpr _View base() const&
requires copy_constructible<_View>
{
return __base_;
}
_LIBCPP_HIDE_FROM_ABI constexpr _View base() && { return std::move(__base_); }
_LIBCPP_HIDE_FROM_ABI constexpr __iterator begin() {
if (!__cached_begin_.__has_value()) {
__cached_begin_.__emplace(__find_next(ranges::begin(__base_)));
}
return {*this, ranges::begin(__base_), *__cached_begin_};
}
_LIBCPP_HIDE_FROM_ABI constexpr auto end() {
if constexpr (common_range<_View>) {
return __iterator{*this, ranges::end(__base_), {}};
} else {
return __sentinel{*this};
}
}
};
template <class _Range, class _Pattern>
split_view(_Range&&, _Pattern&&) -> split_view<views::all_t<_Range>, views::all_t<_Pattern>>;
template <forward_range _Range>
split_view(_Range&&, range_value_t<_Range>) -> split_view<views::all_t<_Range>, single_view<range_value_t<_Range>>>;
template <forward_range _View, forward_range _Pattern>
requires view<_View> && view<_Pattern> &&
indirectly_comparable<iterator_t<_View>, iterator_t<_Pattern>, ranges::equal_to>
struct split_view<_View, _Pattern>::__iterator {
private:
split_view* __parent_ = nullptr;
_LIBCPP_NO_UNIQUE_ADDRESS iterator_t<_View> __cur_ = iterator_t<_View>();
_LIBCPP_NO_UNIQUE_ADDRESS subrange<iterator_t<_View>> __next_ = subrange<iterator_t<_View>>();
bool __trailing_empty_ = false;
friend struct __sentinel;
public:
using iterator_concept = forward_iterator_tag;
using iterator_category = input_iterator_tag;
using value_type = subrange<iterator_t<_View>>;
using difference_type = range_difference_t<_View>;
_LIBCPP_HIDE_FROM_ABI __iterator() = default;
_LIBCPP_HIDE_FROM_ABI constexpr __iterator(
split_view<_View, _Pattern>& __parent, iterator_t<_View> __current, subrange<iterator_t<_View>> __next)
: __parent_(std::addressof(__parent)), __cur_(std::move(__current)), __next_(std::move(__next)) {}
_LIBCPP_HIDE_FROM_ABI constexpr iterator_t<_View> base() const { return __cur_; }
_LIBCPP_HIDE_FROM_ABI constexpr value_type operator*() const { return {__cur_, __next_.begin()}; }
_LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator++() {
__cur_ = __next_.begin();
if (__cur_ != ranges::end(__parent_->__base_)) {
__cur_ = __next_.end();
if (__cur_ == ranges::end(__parent_->__base_)) {
__trailing_empty_ = true;
__next_ = {__cur_, __cur_};
} else {
__next_ = __parent_->__find_next(__cur_);
}
} else {
__trailing_empty_ = false;
}
return *this;
}
_LIBCPP_HIDE_FROM_ABI constexpr __iterator operator++(int) {
auto __tmp = *this;
++*this;
return __tmp;
}
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __iterator& __x, const __iterator& __y) {
return __x.__cur_ == __y.__cur_ && __x.__trailing_empty_ == __y.__trailing_empty_;
}
};
template <forward_range _View, forward_range _Pattern>
requires view<_View> && view<_Pattern> &&
indirectly_comparable<iterator_t<_View>, iterator_t<_Pattern>, ranges::equal_to>
struct split_view<_View, _Pattern>::__sentinel {
private:
_LIBCPP_NO_UNIQUE_ADDRESS sentinel_t<_View> __end_ = sentinel_t<_View>();
_LIBCPP_HIDE_FROM_ABI static constexpr bool __equals(const __iterator& __x, const __sentinel& __y) {
return __x.__cur_ == __y.__end_ && !__x.__trailing_empty_;
}
public:
_LIBCPP_HIDE_FROM_ABI __sentinel() = default;
_LIBCPP_HIDE_FROM_ABI constexpr explicit __sentinel(split_view<_View, _Pattern>& __parent)
: __end_(ranges::end(__parent.__base_)) {}
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __iterator& __x, const __sentinel& __y) {
return __equals(__x, __y);
}
};
namespace views {
namespace __split_view {
struct __fn : __range_adaptor_closure<__fn> {
// clang-format off
template <class _Range, class _Pattern>
_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI
constexpr auto operator()(_Range&& __range, _Pattern&& __pattern) const
noexcept(noexcept(split_view(std::forward<_Range>(__range), std::forward<_Pattern>(__pattern))))
-> decltype( split_view(std::forward<_Range>(__range), std::forward<_Pattern>(__pattern)))
{ return split_view(std::forward<_Range>(__range), std::forward<_Pattern>(__pattern)); }
// clang-format on
template <class _Pattern>
requires constructible_from<decay_t<_Pattern>, _Pattern>
_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Pattern&& __pattern) const
noexcept(is_nothrow_constructible_v<decay_t<_Pattern>, _Pattern>) {
return __range_adaptor_closure_t(std::__bind_back(*this, std::forward<_Pattern>(__pattern)));
}
};
} // namespace __split_view
inline namespace __cpo {
inline constexpr auto split = __split_view::__fn{};
} // namespace __cpo
} // namespace views
} // namespace ranges
#endif // _LIBCPP_STD_VER >= 20
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___RANGES_SPLIT_VIEW_H
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