boost/xpressive/detail/dynamic/matchable.hpp
///////////////////////////////////////////////////////////////////////////////
// matchable.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_DYNAMIC_MATCHABLE_HPP_EAN_10_04_2005
#define BOOST_XPRESSIVE_DETAIL_DYNAMIC_MATCHABLE_HPP_EAN_10_04_2005
// MS compatible compilers support #pragma once
#if defined(_MSC_VER)
# pragma once
#endif
#include <boost/assert.hpp>
#include <boost/mpl/assert.hpp>
#include <boost/intrusive_ptr.hpp>
#include <boost/throw_exception.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/xpressive/detail/core/quant_style.hpp>
#include <boost/xpressive/detail/utility/counted_base.hpp>
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/dynamic/sequence.hpp>
#include <boost/xpressive/regex_error.hpp>
namespace boost { namespace xpressive { namespace detail
{
//////////////////////////////////////////////////////////////////////////
// quant_spec
struct quant_spec
{
unsigned int min_;
unsigned int max_;
bool greedy_;
std::size_t *hidden_mark_count_;
};
///////////////////////////////////////////////////////////////////////////////
// matchable
template<typename BidiIter>
struct matchable
{
typedef BidiIter iterator_type;
typedef typename iterator_value<iterator_type>::type char_type;
virtual ~matchable() {}
virtual bool match(match_state<BidiIter> &state) const = 0;
};
///////////////////////////////////////////////////////////////////////////////
// matchable_ex
template<typename BidiIter>
struct matchable_ex
: matchable<BidiIter>
, counted_base<matchable_ex<BidiIter> >
{
typedef BidiIter iterator_type;
typedef typename iterator_value<iterator_type>::type char_type;
virtual void link(xpression_linker<char_type> &) const
{
}
virtual void peek(xpression_peeker<char_type> &peeker) const
{
peeker.fail();
}
virtual void repeat(quant_spec const &, sequence<BidiIter> &) const
{
BOOST_THROW_EXCEPTION(
regex_error(regex_constants::error_badrepeat, "expression cannot be quantified")
);
}
///////////////////////////////////////////////////////////////////////////////////////////////
// The following 4 functions (push_match, top_match, pop_match and skip_match) are
// used to implement looping and branching across the matchers. Call push_match to record
// a position. Then, another matcher further down the xpression chain has the
// option to call either top_match, pop_match or skip_match. top_match and pop_match will
// jump back to the place recorded by push_match, whereas skip_match will skip the jump and
// pass execution down the xpression chain. top_match will leave the xpression on top of the
// stack, whereas pop_match will remove it. Each function comes in 2 flavors: one for
// statically bound xpressions and one for dynamically bound xpressions.
//
template<typename Top>
bool push_match(match_state<BidiIter> &state) const
{
BOOST_MPL_ASSERT((is_same<Top, matchable_ex<BidiIter> >));
return this->match(state);
}
static bool top_match(match_state<BidiIter> &state, void const *top)
{
return static_cast<matchable_ex<BidiIter> const *>(top)->match(state);
}
static bool pop_match(match_state<BidiIter> &state, void const *top)
{
return static_cast<matchable_ex<BidiIter> const *>(top)->match(state);
}
bool skip_match(match_state<BidiIter> &state) const
{
return this->match(state);
}
};
///////////////////////////////////////////////////////////////////////////////
// shared_matchable
template<typename BidiIter>
struct shared_matchable
{
typedef BidiIter iterator_type;
typedef typename iterator_value<BidiIter>::type char_type;
typedef intrusive_ptr<matchable_ex<BidiIter> const> matchable_ptr;
BOOST_STATIC_CONSTANT(std::size_t, width = unknown_width::value);
BOOST_STATIC_CONSTANT(bool, pure = false);
shared_matchable(matchable_ptr const &xpr = matchable_ptr())
: xpr_(xpr)
{
}
bool operator !() const
{
return !this->xpr_;
}
friend bool operator ==(shared_matchable<BidiIter> const &left, shared_matchable<BidiIter> const &right)
{
return left.xpr_ == right.xpr_;
}
friend bool operator !=(shared_matchable<BidiIter> const &left, shared_matchable<BidiIter> const &right)
{
return left.xpr_ != right.xpr_;
}
matchable_ptr const &matchable() const
{
return this->xpr_;
}
bool match(match_state<BidiIter> &state) const
{
return this->xpr_->match(state);
}
void link(xpression_linker<char_type> &linker) const
{
this->xpr_->link(linker);
}
void peek(xpression_peeker<char_type> &peeker) const
{
this->xpr_->peek(peeker);
}
// BUGBUG yuk!
template<typename Top>
bool push_match(match_state<BidiIter> &state) const
{
BOOST_MPL_ASSERT((is_same<Top, matchable_ex<BidiIter> >));
return this->match(state);
}
private:
matchable_ptr xpr_;
};
}}} // namespace boost::xpressive::detail
#endif