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///////////////////////////////////////////////////////////////////////////////
// alternate_matcher.hpp
//
// 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_MATCHER_ALTERNATE_MATCHER_HPP_EAN_10_04_2005
#define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_ALTERNATE_MATCHER_HPP_EAN_10_04_2005
// MS compatible compilers support #pragma once
#if defined(_MSC_VER)
# pragma once
#endif
#include <boost/version.hpp>
#if BOOST_VERSION <= 103200
// WORKAROUND for Fusion bug in Boost 1.32
namespace boost { namespace fusion
{
namespace detail { struct iterator_root; }
using detail::iterator_root;
}}
#endif
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/core/quant_style.hpp>
#include <boost/xpressive/detail/core/state.hpp>
#include <boost/xpressive/detail/dynamic/matchable.hpp>
#include <boost/xpressive/detail/utility/hash_peek_bitset.hpp>
#include <boost/xpressive/detail/utility/algorithm.hpp>
#include <boost/xpressive/detail/utility/any.hpp>
namespace boost { namespace xpressive { namespace detail
{
///////////////////////////////////////////////////////////////////////////////
// alt_match_pred
//
template<typename BidiIter, typename Next>
struct alt_match_pred
{
alt_match_pred(match_state<BidiIter> &state)
: state_(&state)
{
}
template<typename Xpr>
bool operator ()(Xpr const &xpr) const
{
return xpr.BOOST_NESTED_TEMPLATE push_match<Next>(*this->state_);
}
private:
match_state<BidiIter> *state_;
};
///////////////////////////////////////////////////////////////////////////////
// alt_match
//
template<typename BidiIter, typename Next>
inline bool alt_match
(
alternates_vector<BidiIter> const &alts, match_state<BidiIter> &state, Next const &
)
{
return detail::any(alts.begin(), alts.end(), alt_match_pred<BidiIter, Next>(state));
}
template<typename Head, typename Tail, typename BidiIter, typename Next>
inline bool alt_match
(
alternates_list<Head, Tail> const &alts, match_state<BidiIter> &state, Next const &
)
{
return fusion::any(alts, alt_match_pred<BidiIter, Next>(state));
}
///////////////////////////////////////////////////////////////////////////////
// alternate_matcher
template<typename Alternates, typename Traits>
struct alternate_matcher
: quant_style<
Alternates::width != unknown_width::value && Alternates::pure ? quant_fixed_width : quant_variable_width
, Alternates::width
, Alternates::pure
>
{
typedef Alternates alternates_type;
typedef typename Traits::char_type char_type;
Alternates alternates_;
mutable hash_peek_bitset<char_type> bset_;
explicit alternate_matcher(Alternates const &alternates = Alternates())
: alternates_(alternates)
, bset_()
{
}
template<typename BidiIter, typename Next>
bool match(match_state<BidiIter> &state, Next const &next) const
{
if(!state.eos() && !this->can_match_(*state.cur_, traits_cast<Traits>(state)))
{
return false;
}
return detail::alt_match(this->alternates_, state, next);
}
detail::width get_width() const
{
// Only called when constructing static regexes, and this is a
// set of same-width alternates where the widths are known at compile
// time, as in: sregex rx = +(_ | 'a' | _n);
BOOST_MPL_ASSERT_RELATION(unknown_width::value, !=, Alternates::width);
return Alternates::width;
}
private:
alternate_matcher &operator =(alternate_matcher const &);
bool can_match_(char_type ch, Traits const &tr) const
{
return this->bset_.test(ch, tr);
}
};
}}}
#endif