Sprout/sprout/algorithm/tristate_lexicographical_compare.hpp
2016-02-25 18:48:28 +09:00

263 lines
10 KiB
C++

/*=============================================================================
Copyright (c) 2011-2016 Bolero MURAKAMI
https://github.com/bolero-MURAKAMI/Sprout
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#ifndef SPROUT_ALGORITHM_TRISTATE_LEXICOGRAPHICAL_COMPARE_HPP
#define SPROUT_ALGORITHM_TRISTATE_LEXICOGRAPHICAL_COMPARE_HPP
#include <iterator>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/detail/algorithm/lexicographical_compare.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/iterator/type_traits/category.hpp>
#include <sprout/iterator/type_traits/common.hpp>
#include <sprout/utility/pair/pair.hpp>
#include <sprout/functional/less.hpp>
#include HDR_ALGORITHM_MIN_MAX_SSCRISK_CEL_OR_SPROUT
namespace sprout {
namespace detail {
template<typename Difference1, typename Difference2>
inline SPROUT_CONSTEXPR int
tristate_lexicographical_compare_impl_ra_check(
Difference1 size1, Difference2 size2, int found
)
{
return found != 2 ? found
: size1 < size2 ? -1
: size1 > size2 ? 1 : 0
;
}
template<typename RandomAccessIterator1, typename RandomAccessIterator2, typename Compare>
inline SPROUT_CONSTEXPR typename std::enable_if<
sprout::is_constant_distance_iterator<RandomAccessIterator1>::value,
int
>::type
tristate_lexicographical_compare(
RandomAccessIterator1 first1, RandomAccessIterator1 last1, RandomAccessIterator2 first2, RandomAccessIterator2 last2, Compare comp,
std::random_access_iterator_tag*
)
{
return first2 == last2 ? (first1 == last1 ? 0 : 1)
: first1 == last1 ? -1
: sprout::detail::tristate_lexicographical_compare_impl_ra_check(
sprout::distance(first1, last1), sprout::distance(first2, last2),
sprout::detail::lexicographical_compare_impl_ra(
first1, first2, comp,
NS_SSCRISK_CEL_OR_SPROUT::min(sprout::distance(first1, last1), sprout::distance(first2, last2)),
2
)
)
;
}
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR int
tristate_lexicographical_compare_impl_check(
InputIterator1 last1, InputIterator2 last2, Compare comp,
sprout::pair<InputIterator1, InputIterator2> const& found
)
{
return found.second == last2 ? (found.first == last1 ? 0 : 1)
: found.first == last1 ? -1
: comp(*found.first, *found.second) ? -1
: comp(*found.second, *found.first) ? 1
: 0
;
}
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR int
tristate_lexicographical_compare(
InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp,
std::input_iterator_tag*
)
{
typedef sprout::pair<InputIterator1, InputIterator2> type;
return sprout::detail::tristate_lexicographical_compare_impl_check(
last1, last2, comp,
sprout::detail::lexicographical_compare_impl(type(first1, first2), last1, last2, comp, 1)
);
}
} // namespace detail
//
// tristate_lexicographical_compare
//
// recursion depth:
// O(log(N1+N2))
//
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR int
tristate_lexicographical_compare(
InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
Compare comp
)
{
typedef typename sprout::common_iterator_category<InputIterator1, InputIterator2>::type* category;
return sprout::detail::tristate_lexicographical_compare(first1, last1, first2, last2, comp, category());
}
template<typename InputIterator1, typename InputIterator2>
inline SPROUT_CONSTEXPR int
tristate_lexicographical_compare(
InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2
)
{
return sprout::tristate_lexicographical_compare(
first1, last1, first2, last2,
sprout::less<>()
);
}
namespace detail {
template<typename RandomAccessIterator1, typename T1, typename RandomAccessIterator2, typename T2, typename Compare>
inline SPROUT_CONSTEXPR int
tristate_lexicographical_compare_2_impl_ra(
RandomAccessIterator1 first1, T1 const& delim1,
RandomAccessIterator2 first2, T2 const& delim2,
Compare comp,
typename std::iterator_traits<RandomAccessIterator1>::difference_type size, int found
)
{
return found != 2 ? found
: size == 1
? !comp(*first2, delim2) && !comp(delim2, *first2)
? !comp(*first1, delim1) && !comp(delim1, *first1) ? 0 : 1
: (!comp(*first1, delim1) && !comp(delim1, *first1)) || comp(*first1, *first2)
? -1
: comp(*first2, *first1) ? 1 : 2
: sprout::detail::tristate_lexicographical_compare_2_impl_ra(
sprout::next(first1, size / 2), delim1, sprout::next(first2, size / 2), delim2, comp,
size - size / 2,
sprout::detail::tristate_lexicographical_compare_2_impl_ra(
first1, delim1, first2, delim2, comp,
size / 2,
2
)
)
;
}
template<typename RandomAccessIterator1, typename T1, typename RandomAccessIterator2, typename T2, typename Compare>
inline SPROUT_CONSTEXPR int
tristate_lexicographical_compare_2(
RandomAccessIterator1 first1, RandomAccessIterator1 last1, T1 const& delim1,
RandomAccessIterator2 first2, RandomAccessIterator2 last2, T2 const& delim2,
Compare comp,
std::random_access_iterator_tag*
)
{
return sprout::detail::tristate_lexicographical_compare_impl_ra_check(
sprout::distance(first1, last1), sprout::distance(first2, last2),
first2 == last2 || first1 == last1
? 2
: sprout::detail::tristate_lexicographical_compare_2_impl_ra(
first1, delim1, first2, delim2, comp,
NS_SSCRISK_CEL_OR_SPROUT::min(sprout::distance(first1, last1), sprout::distance(first2, last2)),
2
)
)
;
}
template<typename InputIterator1, typename T1, typename InputIterator2, typename T2, typename Compare>
inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
tristate_lexicographical_compare_impl_1(
sprout::pair<InputIterator1, InputIterator2> const& current,
InputIterator1 last1, T1 const& delim1, InputIterator2 last2, T2 const& delim2, Compare comp,
typename std::iterator_traits<InputIterator1>::difference_type n
)
{
typedef sprout::pair<InputIterator1, InputIterator2> type;
return current.second == last2 || current.first == last1 ? current
: n == 1
? !comp(*current.second, delim2) && !comp(delim2, *current.second)
? type(!comp(*current.first, delim1) && !comp(delim1, *current.first) ? last1 : current.first, last2)
: (!comp(*current.first, delim1) && !comp(delim1, *current.first)) || comp(*current.first, *current.second)
? type(last1, current.second)
: comp(*current.second, *current.first) ? type(current.first, last2)
: type(sprout::next(current.first), sprout::next(current.second))
: sprout::detail::tristate_lexicographical_compare_impl_1(
sprout::detail::tristate_lexicographical_compare_impl_1(
current,
last1, delim1, last2, delim2, comp, n / 2
),
last1, delim1, last2, delim2, comp, n - n / 2
)
;
}
template<typename InputIterator1, typename T1, typename InputIterator2, typename T2, typename Compare>
inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
tristate_lexicographical_compare_impl(
sprout::pair<InputIterator1, InputIterator2> const& current,
InputIterator1 last1, T1 const& delim1, InputIterator2 last2, T2 const& delim2, Compare comp,
typename std::iterator_traits<InputIterator1>::difference_type n
)
{
return current.second == last2 || current.first == last1 ? current
: sprout::detail::tristate_lexicographical_compare_impl(
sprout::detail::tristate_lexicographical_compare_impl_1(
current,
last1, delim1, last2, delim2, comp, n
),
last1, delim1, last2, delim2, comp, n * 2
)
;
}
template<typename InputIterator1, typename T1, typename InputIterator2, typename T2, typename Compare>
inline SPROUT_CONSTEXPR int
tristate_lexicographical_compare_2(
InputIterator1 first1, InputIterator1 last1, T1 const& delim1,
InputIterator2 first2, InputIterator2 last2, T2 const& delim2,
Compare comp,
std::input_iterator_tag*
)
{
typedef sprout::pair<InputIterator1, InputIterator2> type;
return sprout::detail::tristate_lexicographical_compare_impl_check(
last1, last2, comp,
sprout::detail::tristate_lexicographical_compare_impl(type(first1, first2), last1, delim1, last2, delim2, comp, 1)
);
}
} // namespace detail
//
// tristate_lexicographical_compare
//
// recursion depth:
// O(log(N1+N2))
//
template<typename InputIterator1, typename T1, typename InputIterator2, typename T2, typename Compare>
inline SPROUT_CONSTEXPR int
tristate_lexicographical_compare(
InputIterator1 first1, InputIterator1 last1, T1 const& delim1,
InputIterator2 first2, InputIterator2 last2, T2 const& delim2,
Compare comp
)
{
typedef typename sprout::common_iterator_category<InputIterator1, InputIterator2>::type* category;
return sprout::detail::tristate_lexicographical_compare_2(first1, last1, delim1, first2, last2, delim2, comp, category());
}
template<typename InputIterator1, typename T1, typename InputIterator2, typename T2>
inline SPROUT_CONSTEXPR int
tristate_lexicographical_compare(
InputIterator1 first1, InputIterator1 last1, T1 const& delim1,
InputIterator2 first2, InputIterator2 last2, T2 const& delim2
)
{
return sprout::tristate_lexicographical_compare(
first1, last1, delim1, first2, last2, delim2,
sprout::less<>()
);
}
} // namespace sprout
#endif // #ifndef SPROUT_ALGORITHM_TRISTATE_LEXICOGRAPHICAL_COMPARE_HPP