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fix recursion depth: cstring algorithm

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bolero-MURAKAMI 2013-01-13 01:16:48 +09:00
parent f26032dce8
commit b51b14efa9
25 changed files with 792 additions and 142 deletions
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146
sprout/cstring/strstr.hpp
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@ -1,24 +1,154 @@
#ifndef SPROUT_CSTRING_STRSTR_HPP
#define SPROUT_CSTRING_STRSTR_HPP
#include <iterator>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/utility/pair.hpp>
#include <sprout/tuple/tuple.hpp>
#include <sprout/type_traits/is_char_type.hpp>
#include <sprout/detail/str.hpp>
namespace sprout {
// Copyright (C) 2011 RiSK (sscrisk)
namespace detail {
template<typename ForwardIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR sprout::tuples::tuple<ForwardIterator1, ForwardIterator2, bool>
strstr_one_impl_1(
sprout::tuples::tuple<ForwardIterator1, ForwardIterator2, bool> const& current,
ForwardIterator1 first1_, typename std::iterator_traits<ForwardIterator1>::difference_type n
)
{
typedef sprout::tuples::tuple<ForwardIterator1, ForwardIterator2, bool> type;
return sprout::tuples::get<2>(current) ? current
: !*sprout::tuples::get<1>(current) ? type(first1_, sprout::tuples::get<1>(current), true)
: !*sprout::tuples::get<0>(current) ? type(sprout::tuples::get<0>(current), sprout::tuples::get<1>(current), true)
: n == 1 ? !(*sprout::tuples::get<0>(current) == *sprout::tuples::get<1>(current))
? type(sprout::next(sprout::tuples::get<0>(current)), sprout::tuples::get<1>(current), true)
: type(sprout::next(sprout::tuples::get<0>(current)), sprout::next(sprout::tuples::get<1>(current)), false)
: sprout::detail::strstr_one_impl_1(
sprout::detail::strstr_one_impl_1(
current,
first1_, n / 2
),
first1_, n - n / 2
)
;
}
template<typename ForwardIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR sprout::tuples::tuple<ForwardIterator1, ForwardIterator2, bool>
strstr_one_impl(
sprout::tuples::tuple<ForwardIterator1, ForwardIterator2, bool> const& current,
ForwardIterator1 first1_, typename std::iterator_traits<ForwardIterator1>::difference_type n
)
{
typedef sprout::tuples::tuple<ForwardIterator1, ForwardIterator2, bool> type;
return sprout::tuples::get<2>(current) ? current
: !*sprout::tuples::get<1>(current) ? type(first1_, sprout::tuples::get<1>(current), true)
: !*sprout::tuples::get<0>(current) ? type(sprout::tuples::get<0>(current), sprout::tuples::get<1>(current), true)
: sprout::detail::strstr_one_impl(
sprout::detail::strstr_one_impl_1(
current,
first1_, n
),
first1_, n * 2
)
;
}
template<typename ForwardIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR ForwardIterator1
strstr_one(ForwardIterator1 first1, ForwardIterator2 first2) {
typedef sprout::tuples::tuple<ForwardIterator1, ForwardIterator2, bool> type;
return sprout::tuples::get<0>(sprout::detail::strstr_one_impl(type(first1, first2, false), first1, 1));
}
template<typename ForwardIterator>
inline SPROUT_CONSTEXPR sprout::pair<ForwardIterator, bool>
strstr_impl_fork(sprout::pair<ForwardIterator, bool> const& current, ForwardIterator searched) {
typedef sprout::pair<ForwardIterator, bool> type;
return searched == current.first || !*searched ? type(searched, true)
: type(sprout::next(current.first), false)
;
}
template<typename ForwardIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR sprout::pair<ForwardIterator1, bool>
strstr_impl_1(
sprout::pair<ForwardIterator1, bool> const& current,
ForwardIterator2 first2,
typename std::iterator_traits<ForwardIterator1>::difference_type n
)
{
typedef sprout::pair<ForwardIterator1, bool> type;
return current.second || !*current.first ? current
: n == 1 ? sprout::detail::strstr_impl_fork(
current,
sprout::detail::strstr_one(current.first, first2)
)
: sprout::detail::strstr_impl_1(
sprout::detail::strstr_impl_1(
current,
first2, n / 2
),
first2, n - n / 2
)
;
}
template<typename ForwardIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR sprout::pair<ForwardIterator1, bool>
strstr_impl(
sprout::pair<ForwardIterator1, bool> const& current,
ForwardIterator2 first2,
typename std::iterator_traits<ForwardIterator1>::difference_type n
)
{
typedef sprout::pair<ForwardIterator1, bool> type;
return current.second || !*current.first ? current
: sprout::detail::strstr_impl(
sprout::detail::strstr_impl_1(
current,
first2, n
),
first2, n * 2
)
;
}
template<typename ForwardIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR ForwardIterator1
strstr(ForwardIterator1 first1, ForwardIterator2 first2) {
typedef sprout::pair<ForwardIterator1, bool> type;
return !*first2 ? first1
: sprout::detail::strstr_impl(type(first1, false), first2, 1).first
;
}
} // namespace detail
// 7.21.5.7 strstr ŠÖ<C5A0>”
//
// recursion depth:
// O(log(N1+N2))
//
inline SPROUT_CONSTEXPR char const*
strstr(char const* s1, char const* s2) {
return !*s2 ? s1
: !*s1 ? nullptr
: *s1 == *s2 && sprout::strstr(s1 + 1, s2 + 1) ? s1
: sprout::strstr(s1 + 1, s2)
;
return sprout::detail::str_find_check(
sprout::detail::strstr(s1, s2)
);
}
inline SPROUT_CONSTEXPR char*
strstr(char* s1, char const* s2) {
return const_cast<char*>(sprout::strstr(const_cast<char const*>(s1), s2));
return sprout::detail::str_find_check(
sprout::detail::strstr(s1, s2)
);
}
template<typename Elem>
inline SPROUT_CONSTEXPR typename std::enable_if<
sprout::is_char_type<Elem>::value,
Elem*
>::type
strstr(Elem* s1, typename std::remove_const<Elem>::type const* s2) {
return sprout::detail::str_find_check(
sprout::detail::strstr(s1, s2)
);
}
} // namespace sprout