acceptingMachine.h

#pragma once
 
#include <string>
#include <functional>
#include <type_traits>
 
namespace TuringSim::Machine {
    enum struct AcceptingStyle {
        NonAccepting,  
        Accepting,  
        Alternating,  
    };
 
    namespace Acceptance {
        enum NodeType {
            Accept,  
            Reject,  
            Universal,  
            Existential,  
        };
 
        template<typename CharT = char, typename Traits = std::char_traits<CharT>>
        std::function<std::basic_ostream<CharT, Traits>&(std::basic_ostream<CharT, Traits>&)> debug(NodeType node) {
            std::function<std::basic_ostream<CharT, Traits>&(std::basic_ostream<CharT, Traits>&)> f =
                    [node] (std::basic_ostream<CharT, Traits>& os) -> std::basic_ostream<CharT, Traits>& {
                        switch(node) {
                            case Accept:
                                return os << "T";
                            case Universal:
                                return os << "A";
                            case Reject:
                                return os << "_|_";
                            case Existential:
                                return os << "E";
                        }
                    };
            return f;
        }
 
        bool decideForEmptySet(NodeType node);
 
        std::optional<bool> toBool(NodeType node);
    }
 
    template<typename TransitionType, AcceptingStyle acceptingStyle>
    class AcceptingMachine;
 
    template<typename TransitionType_>
    class AcceptingMachine<TransitionType_, AcceptingStyle::NonAccepting> {
    public:
        typedef TransitionType_ TransitionType;
 
        typedef typename TransitionType::StateType StateType;
 
        typedef typename TransitionType::StorageType StorageType;
 
        typedef std::false_type IsAccepting;
 
        typedef std::false_type IsAlternating;
 
        AcceptingMachine() = default;
 
        AcceptingMachine(const AcceptingMachine&) = default;
 
        AcceptingMachine(AcceptingMachine&&) = default;
 
        AcceptingMachine& operator=(const AcceptingMachine&) = default;
 
        AcceptingMachine& operator=(AcceptingMachine&&) = default;
 
        virtual ~AcceptingMachine() = default;
    };
 
    template<typename TransitionType_>
    class AcceptingMachine<TransitionType_, AcceptingStyle::Accepting> {
    public:
        typedef TransitionType_ TransitionType;
 
        typedef typename TransitionType::StateType StateType;
 
        typedef typename TransitionType::StorageType StorageType;
 
        typedef std::true_type IsAccepting;
 
        typedef std::false_type IsAlternating;
 
        AcceptingMachine() = default;
 
        AcceptingMachine(const AcceptingMachine&) = default;
 
        AcceptingMachine(AcceptingMachine&&) = default;
 
        AcceptingMachine& operator=(const AcceptingMachine&) = default;
 
        AcceptingMachine& operator=(AcceptingMachine&&) = default;
 
        virtual ~AcceptingMachine() = default;
 
        virtual bool isAcceptingConfiguration(const StateType& state, const StorageType& storage) const noexcept = 0;
    };
 
    template<typename TransitionType_>
    class AcceptingMachine<TransitionType_, AcceptingStyle::Alternating> {
    public:
        typedef TransitionType_ TransitionType;
 
        typedef typename TransitionType::StateType StateType;
 
        typedef typename TransitionType::StorageType StorageType;
 
        typedef std::true_type IsAccepting;
 
        typedef std::true_type IsAlternating;
 
        AcceptingMachine() = default;
 
        AcceptingMachine(const AcceptingMachine&) = default;
 
        AcceptingMachine(AcceptingMachine&&) = default;
 
        AcceptingMachine& operator=(const AcceptingMachine&) = default;
 
        AcceptingMachine& operator=(AcceptingMachine&&) = default;
 
        virtual ~AcceptingMachine() = default;
 
        virtual Acceptance::NodeType isAcceptingConfiguration(const StateType& state, const StorageType& storage) const noexcept = 0;
 
        virtual bool isInitiallyUniversal() const noexcept = 0;
    };
}