automaton_state_label.h

#ifndef PASTELSYS_AUTOMATON_STATE_LABEL_H
#define PASTELSYS_AUTOMATON_STATE_LABEL_H

#include "pastel/sys/automaton/automaton_fwd.h"

namespace Pastel
{

    template <
        typename Symbol,
        typename StateData,
        typename TransitionData>
    class Automaton_Fwd;

    namespace Automaton_
    {

        template <
            typename Symbol,
            typename StateData,
            typename TransitionData>
        class StateLabel
            : public Automaton_Fwd<Symbol, StateData, TransitionData>::StateData_Class
        {
        private:
            static constexpr uint32 FINAL_FLAG = 0x00000001;
            static constexpr uint32 START_FLAG = 0x00000002;

            typedef Automaton_Fwd<Symbol, StateData, TransitionData>
                Fwd;

            PASTEL_FWD(Final_Iterator);
            PASTEL_FWD(Start_Iterator);
            PASTEL_FWD(StateData_Class);

        public:
            // FIX: Delete after emplace becomes available in Visual Studio.
            StateLabel(StateLabel&& that)
                : StateData_Class(std::move((StateData_Class&&)that))
                , finalPosition_(std::move(that.finalPosition_))
                , startPosition_(std::move(that.startPosition_))
                , flags_(std::move(that.flags_))
            {
            }

            //! Assigns to the contained data.
            template <typename Type>
            StateLabel& operator=(Type&& that)
            {
                ((StateData_Class&)*this) = std::forward<Type>(that);
                return *this;
            }

            bool final() const
            {
                return (flags_ & FINAL_FLAG) != 0;
            }

            bool start() const
            {
                return (flags_ & START_FLAG) != 0;
            }

        private:
            StateLabel() = delete;
            StateLabel(const StateLabel& that) = delete;
            StateLabel& operator=(const StateLabel&) = delete;

        private:
            template <
                typename, typename,
                typename, typename>
                friend class Pastel::Automaton;

            StateLabel(
                StateData_Class stateData)
                : StateData_Class(std::move(stateData))
                , finalPosition_()
                , startPosition_()
                , flags_(0)
            {
            }

            void setStart(bool start)
            {
                flags_ |= START_FLAG;
                if (!start)
                {
                    flags_ ^= START_FLAG;
                }
            }

            void setFinal(bool final)
            {
                flags_ |= FINAL_FLAG;
                if (!final)
                {
                    flags_ ^= FINAL_FLAG;
                }
            }

            /*
           Is it really necessary to keep the flags here?
           The answer is yes for two reasons. First, we want a
           state to be able to tell whether its start/final
           without consulting the automaton. Second, even if the
           first reason wasn't included, we want startPosition
           and finalPosition to be container-independent; splicing
           the startSet or the finalSet of an automaton to another
           should not break anything (checking against startSet_.end()
           or finalSet_.end() would break on splicing).
           */

            Final_Iterator finalPosition_;
            Start_Iterator startPosition_;
            uint32 flags_;
        };

    }

}

#endif