Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // matchable.hpp
Chris@16: //
Chris@16: //  Copyright 2008 Eric Niebler. Distributed under the Boost
Chris@16: //  Software License, Version 1.0. (See accompanying file
Chris@16: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_XPRESSIVE_DETAIL_DYNAMIC_MATCHABLE_HPP_EAN_10_04_2005
Chris@16: #define BOOST_XPRESSIVE_DETAIL_DYNAMIC_MATCHABLE_HPP_EAN_10_04_2005
Chris@16: 
Chris@16: // MS compatible compilers support #pragma once
Chris@101: #if defined(_MSC_VER)
Chris@16: # pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/mpl/assert.hpp>
Chris@16: #include <boost/intrusive_ptr.hpp>
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: #include <boost/xpressive/detail/core/quant_style.hpp>
Chris@16: #include <boost/xpressive/detail/utility/counted_base.hpp>
Chris@16: #include <boost/xpressive/detail/detail_fwd.hpp>
Chris@16: #include <boost/xpressive/detail/dynamic/sequence.hpp>
Chris@16: #include <boost/xpressive/regex_error.hpp>
Chris@16: 
Chris@16: namespace boost { namespace xpressive { namespace detail
Chris@16: {
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////
Chris@16: // quant_spec
Chris@16: struct quant_spec
Chris@16: {
Chris@16:     unsigned int min_;
Chris@16:     unsigned int max_;
Chris@16:     bool greedy_;
Chris@16:     std::size_t *hidden_mark_count_;
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // matchable
Chris@16: template<typename BidiIter>
Chris@16: struct matchable
Chris@16: {
Chris@16:     typedef BidiIter iterator_type;
Chris@16:     typedef typename iterator_value<iterator_type>::type char_type;
Chris@16:     virtual ~matchable() {}
Chris@16:     virtual bool match(match_state<BidiIter> &state) const = 0;
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // matchable_ex
Chris@16: template<typename BidiIter>
Chris@16: struct matchable_ex
Chris@16:   : matchable<BidiIter>
Chris@16:   , counted_base<matchable_ex<BidiIter> >
Chris@16: {
Chris@16:     typedef BidiIter iterator_type;
Chris@16:     typedef typename iterator_value<iterator_type>::type char_type;
Chris@16: 
Chris@16:     virtual void link(xpression_linker<char_type> &) const
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     virtual void peek(xpression_peeker<char_type> &peeker) const
Chris@16:     {
Chris@16:         peeker.fail();
Chris@16:     }
Chris@16: 
Chris@16:     virtual void repeat(quant_spec const &, sequence<BidiIter> &) const
Chris@16:     {
Chris@16:         BOOST_THROW_EXCEPTION(
Chris@16:             regex_error(regex_constants::error_badrepeat, "expression cannot be quantified")
Chris@16:         );
Chris@16:     }
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////////////////////////
Chris@16:     // The following 4 functions (push_match, top_match, pop_match and skip_match) are
Chris@16:     // used to implement looping and branching across the matchers. Call push_match to record
Chris@16:     // a position. Then, another matcher further down the xpression chain has the
Chris@16:     // option to call either top_match, pop_match or skip_match. top_match and pop_match will
Chris@16:     // jump back to the place recorded by push_match, whereas skip_match will skip the jump and
Chris@16:     // pass execution down the xpression chain. top_match will leave the xpression on top of the
Chris@16:     // stack, whereas pop_match will remove it. Each function comes in 2 flavors: one for
Chris@16:     // statically bound xpressions and one for dynamically bound xpressions.
Chris@16:     //
Chris@16: 
Chris@16:     template<typename Top>
Chris@16:     bool push_match(match_state<BidiIter> &state) const
Chris@16:     {
Chris@16:         BOOST_MPL_ASSERT((is_same<Top, matchable_ex<BidiIter> >));
Chris@16:         return this->match(state);
Chris@16:     }
Chris@16: 
Chris@16:     static bool top_match(match_state<BidiIter> &state, void const *top)
Chris@16:     {
Chris@16:         return static_cast<matchable_ex<BidiIter> const *>(top)->match(state);
Chris@16:     }
Chris@16: 
Chris@16:     static bool pop_match(match_state<BidiIter> &state, void const *top)
Chris@16:     {
Chris@16:         return static_cast<matchable_ex<BidiIter> const *>(top)->match(state);
Chris@16:     }
Chris@16: 
Chris@16:     bool skip_match(match_state<BidiIter> &state) const
Chris@16:     {
Chris@16:         return this->match(state);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // shared_matchable
Chris@16: template<typename BidiIter>
Chris@16: struct shared_matchable
Chris@16: {
Chris@16:     typedef BidiIter iterator_type;
Chris@16:     typedef typename iterator_value<BidiIter>::type char_type;
Chris@16:     typedef intrusive_ptr<matchable_ex<BidiIter> const> matchable_ptr;
Chris@16: 
Chris@16:     BOOST_STATIC_CONSTANT(std::size_t, width = unknown_width::value);
Chris@16:     BOOST_STATIC_CONSTANT(bool, pure = false);
Chris@16: 
Chris@16:     shared_matchable(matchable_ptr const &xpr = matchable_ptr())
Chris@16:       : xpr_(xpr)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     bool operator !() const
Chris@16:     {
Chris@16:         return !this->xpr_;
Chris@16:     }
Chris@16: 
Chris@16:     friend bool operator ==(shared_matchable<BidiIter> const &left, shared_matchable<BidiIter> const &right)
Chris@16:     {
Chris@16:         return left.xpr_ == right.xpr_;
Chris@16:     }
Chris@16: 
Chris@16:     friend bool operator !=(shared_matchable<BidiIter> const &left, shared_matchable<BidiIter> const &right)
Chris@16:     {
Chris@16:         return left.xpr_ != right.xpr_;
Chris@16:     }
Chris@16: 
Chris@16:     matchable_ptr const &matchable() const
Chris@16:     {
Chris@16:         return this->xpr_;
Chris@16:     }
Chris@16: 
Chris@16:     bool match(match_state<BidiIter> &state) const
Chris@16:     {
Chris@16:         return this->xpr_->match(state);
Chris@16:     }
Chris@16: 
Chris@16:     void link(xpression_linker<char_type> &linker) const
Chris@16:     {
Chris@16:         this->xpr_->link(linker);
Chris@16:     }
Chris@16: 
Chris@16:     void peek(xpression_peeker<char_type> &peeker) const
Chris@16:     {
Chris@16:         this->xpr_->peek(peeker);
Chris@16:     }
Chris@16: 
Chris@16:     // BUGBUG yuk!
Chris@16:     template<typename Top>
Chris@16:     bool push_match(match_state<BidiIter> &state) const
Chris@16:     {
Chris@16:         BOOST_MPL_ASSERT((is_same<Top, matchable_ex<BidiIter> >));
Chris@16:         return this->match(state);
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     matchable_ptr xpr_;
Chris@16: };
Chris@16: 
Chris@16: }}} // namespace boost::xpressive::detail
Chris@16: 
Chris@16: #endif