boost/xpressive/detail/core/finder.hpp
/// Contains the definition of the basic_regex\<\> class template and its associated helper functions.
//
// Copyright 2008 Eric Niebler. 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 BOOST_XPRESSIVE_DETAIL_CORE_FINDER_HPP_EAN_10_04_2005
#define BOOST_XPRESSIVE_DETAIL_CORE_FINDER_HPP_EAN_10_04_2005
// MS compatible compilers support #pragma once
#if defined(_MSC_VER)
# pragma once
# pragma warning(push)
# pragma warning(disable : 4189) // local variable is initialized but not referenced
#endif
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/core/regex_impl.hpp>
#include <boost/xpressive/detail/utility/boyer_moore.hpp>
#include <boost/xpressive/detail/utility/hash_peek_bitset.hpp>
namespace boost { namespace xpressive { namespace detail
{
///////////////////////////////////////////////////////////////////////////////
// boyer_moore_finder
//
template<typename BidiIter, typename Traits>
struct boyer_moore_finder
: finder<BidiIter>
{
typedef typename iterator_value<BidiIter>::type char_type;
boyer_moore_finder(char_type const *begin, char_type const *end, Traits const &tr, bool icase)
: bm_(begin, end, tr, icase)
{
}
bool ok_for_partial_matches() const
{
return false;
}
bool operator ()(match_state<BidiIter> &state) const
{
Traits const &tr = traits_cast<Traits>(state);
state.cur_ = this->bm_.find(state.cur_, state.end_, tr);
return state.cur_ != state.end_;
}
private:
boyer_moore_finder(boyer_moore_finder const &);
boyer_moore_finder &operator =(boyer_moore_finder const &);
boyer_moore<BidiIter, Traits> bm_;
};
///////////////////////////////////////////////////////////////////////////////
// hash_peek_finder
//
template<typename BidiIter, typename Traits>
struct hash_peek_finder
: finder<BidiIter>
{
typedef typename iterator_value<BidiIter>::type char_type;
hash_peek_finder(hash_peek_bitset<char_type> const &bset)
: bset_(bset)
{
}
bool operator ()(match_state<BidiIter> &state) const
{
Traits const &tr = traits_cast<Traits>(state);
state.cur_ = (this->bset_.icase()
? this->find_(state.cur_, state.end_, tr, mpl::true_())
: this->find_(state.cur_, state.end_, tr, mpl::false_()));
return state.cur_ != state.end_;
}
private:
hash_peek_finder(hash_peek_finder const &);
hash_peek_finder &operator =(hash_peek_finder const &);
template<typename ICase>
BidiIter find_(BidiIter begin, BidiIter end, Traits const &tr, ICase) const
{
for(; begin != end && !this->bset_.test(*begin, tr, ICase()); ++begin)
;
return begin;
}
hash_peek_bitset<char_type> bset_;
};
///////////////////////////////////////////////////////////////////////////////
// line_start_finder
//
template<typename BidiIter, typename Traits, std::size_t Size = sizeof(typename iterator_value<BidiIter>::type)>
struct line_start_finder
: finder<BidiIter>
{
typedef typename iterator_value<BidiIter>::type char_type;
typedef typename iterator_difference<BidiIter>::type diff_type;
typedef typename Traits::char_class_type char_class_type;
line_start_finder(Traits const &tr)
: newline_(lookup_classname(tr, "newline"))
{
}
bool operator ()(match_state<BidiIter> &state) const
{
if(state.bos() && state.flags_.match_bol_)
{
return true;
}
Traits const &tr = traits_cast<Traits>(state);
BidiIter cur = state.cur_;
BidiIter const end = state.end_;
std::advance(cur, static_cast<diff_type>(-!state.bos()));
for(; cur != end; ++cur)
{
if(tr.isctype(*cur, this->newline_))
{
state.cur_ = ++cur;
return true;
}
}
return false;
}
private:
line_start_finder(line_start_finder const &);
line_start_finder &operator =(line_start_finder const &);
char_class_type newline_;
};
///////////////////////////////////////////////////////////////////////////////
// line_start_finder
//
template<typename BidiIter, typename Traits>
struct line_start_finder<BidiIter, Traits, 1u>
: finder<BidiIter>
{
typedef typename iterator_value<BidiIter>::type char_type;
typedef typename iterator_difference<BidiIter>::type diff_type;
typedef typename Traits::char_class_type char_class_type;
line_start_finder(Traits const &tr)
{
char_class_type newline = lookup_classname(tr, "newline");
for(int j = 0; j < 256; ++j)
{
this->bits_[j] = tr.isctype(static_cast<char_type>(static_cast<unsigned char>(j)), newline);
}
}
bool operator ()(match_state<BidiIter> &state) const
{
if(state.bos() && state.flags_.match_bol_)
{
return true;
}
BidiIter cur = state.cur_;
BidiIter const end = state.end_;
std::advance(cur, static_cast<diff_type>(-!state.bos()));
for(; cur != end; ++cur)
{
if(this->bits_[static_cast<unsigned char>(*cur)])
{
state.cur_ = ++cur;
return true;
}
}
return false;
}
private:
line_start_finder(line_start_finder const &);
line_start_finder &operator =(line_start_finder const &);
bool bits_[256];
};
///////////////////////////////////////////////////////////////////////////////
// leading_simple_repeat_finder
//
template<typename BidiIter>
struct leading_simple_repeat_finder
: finder<BidiIter>
{
leading_simple_repeat_finder()
: finder<BidiIter>()
{}
bool operator ()(match_state<BidiIter> &state) const
{
state.cur_ = state.next_search_;
return true;
}
private:
leading_simple_repeat_finder(leading_simple_repeat_finder const &);
leading_simple_repeat_finder &operator =(leading_simple_repeat_finder const &);
};
}}}
#if defined(_MSC_VER)
# pragma warning(pop)
#endif
#endif