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///////////////////////////////////////////////////////////////////////////////
// assert_word_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_ASSERT_WORD_MATCHER_HPP_EAN_10_04_2005
#define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_ASSERT_WORD_MATCHER_HPP_EAN_10_04_2005
// MS compatible compilers support #pragma once
#if defined(_MSC_VER)
# pragma once
#endif
#include <boost/assert.hpp>
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/core/quant_style.hpp>
#include <boost/xpressive/detail/utility/ignore_unused.hpp>
#include <boost/xpressive/detail/core/state.hpp>
namespace boost { namespace xpressive { namespace detail
{
///////////////////////////////////////////////////////////////////////////////
// word_boundary
//
template<typename IsBoundary>
struct word_boundary
{
template<typename BidiIter>
static bool eval(bool prevword, bool thisword, match_state<BidiIter> &state)
{
if((state.flags_.match_not_bow_ && state.bos()) || (state.flags_.match_not_eow_ && state.eos()))
{
return !IsBoundary::value;
}
return IsBoundary::value == (prevword != thisword);
}
};
///////////////////////////////////////////////////////////////////////////////
// word_begin
//
struct word_begin
{
template<typename BidiIter>
static bool eval(bool prevword, bool thisword, match_state<BidiIter> &state)
{
if(state.flags_.match_not_bow_ && state.bos())
{
return false;
}
return !prevword && thisword;
}
};
///////////////////////////////////////////////////////////////////////////////
// word_end
//
struct word_end
{
template<typename BidiIter>
static bool eval(bool prevword, bool thisword, match_state<BidiIter> &state)
{
if(state.flags_.match_not_eow_ && state.eos())
{
return false;
}
return prevword && !thisword;
}
};
///////////////////////////////////////////////////////////////////////////////
// assert_word_matcher
//
template<typename Cond, typename Traits>
struct assert_word_matcher
: quant_style_assertion
{
typedef typename Traits::char_type char_type;
typedef typename Traits::char_class_type char_class_type;
assert_word_matcher(Traits const &tr)
: word_(lookup_classname(tr, "w"))
{
BOOST_ASSERT(0 != this->word_);
}
assert_word_matcher(char_class_type word)
: word_(word)
{}
bool is_word(Traits const &tr, char_type ch) const
{
detail::ignore_unused(tr);
return tr.isctype(tr.translate(ch), this->word_);
}
template<typename BidiIter, typename Next>
bool match(match_state<BidiIter> &state, Next const &next) const
{
BidiIter cur = state.cur_;
bool const thisword = !state.eos() && this->is_word(traits_cast<Traits>(state), *cur);
bool const prevword = (!state.bos() || state.flags_.match_prev_avail_)
&& this->is_word(traits_cast<Traits>(state), *--cur);
return Cond::eval(prevword, thisword, state) && next.match(state);
}
char_class_type word() const
{
return this->word_;
}
private:
char_class_type word_;
};
}}}
#endif