s2ga/s2ga.hpp

#include <random>
#include <bitset>
#include <magic_enum/magic_enum.hpp>
#include <type_traits>
#include <iostream>
#include <format>
#include <vector>

namespace s2ga
{
    template<class... T>
    struct always_false: std::false_type
    {
    };

    class lehmer64
    {
    public:
        lehmer64(__uint128_t seed = 0)
        {
            this->seed(seed);
        }

        void seed(__uint128_t z)
        {
            if(z == 0)
            {
                z = 0xC0FFEE;
            }

            s = z;
        }

        uint64_t operator()() noexcept
        {
            s *= 0xda942042e4dd58b5;
            return s >> 64;
        }

        static constexpr uint64_t min()
        {
            return 0;
        }

        static constexpr uint64_t max()
        {
            return UINT64_MAX;
        }

        template<typename T>
        T random(T min, T max)
        {
            if constexpr(std::is_integral_v<T>)
            {
                return std::uniform_int_distribution<T>(min, max)(*this);
            }
            else if constexpr(std::is_floating_point_v<T>)
            {
                return std::uniform_real_distribution<T>(min, max)(*this);
            }
            else
            {
                static_assert(always_false<T>::value,
                              "unsupported distribution type");
            }
        }

    private:
        __uint128_t s;
    };

    static_assert(std::uniform_random_bit_generator<lehmer64>);

    template<typename E, typename... Args>
    requires std::is_enum_v<E> && ((std::is_same_v<E, Args>), ...)
    std::bitset<magic_enum::enum_count<E>()> bm(const Args&... v) //aka "bitmask"
    {
        constexpr size_t N = magic_enum::enum_count<E>();
        std::bitset<N> bitmask;

        ((bitmask.set(magic_enum::enum_integer(v))), ...);
        return bitmask;
    }

    template<typename E>
    requires std::is_enum_v<E>
    struct action 
    {
        static constexpr size_t N = magic_enum::enum_count<E>();

        std::string name = "ACTION";
        float cost = 1.0f;
        
        std::bitset<N> positive_effects{};
        std::bitset<N> negative_effects{};
        std::bitset<N> positive_preconds{};
        std::bitset<N> negative_preconds{};

        bool preconds_met(const std::bitset<N>& state) const
        {
            return ((state & positive_preconds) == positive_preconds) && 
                (state & ~negative_preconds).none();
        }

        std::bitset<N> apply(const std::bitset<N>& state) const
        {
            return (state | positive_effects) & ~negative_effects;
        }

        void print()
        {
            std::cout << std::format("[{}, {}]", name, cost) << std::endl;

            if(positive_effects.any() || negative_effects.any())
            {
                std::cout << "Effects:" << std::endl;
                for(size_t i = 0; i < N; ++i)
                {
                    if(positive_effects.test(i) || negative_effects.test(i))
                    {
                        auto enum_value = magic_enum::enum_cast<E>(i).value();
                        auto value_name = magic_enum::enum_name(enum_value);

                        std::cout << std::format(" {}{}", 
                                negative_effects.test(i) ? "-" : "+",
                                value_name) << std::endl;
                    }
                }
            }
        
            if(positive_preconds.any() || negative_preconds.any())
            {
                std::cout << "Preconditions:" << std::endl;
                for(size_t i = 0; i < N; ++i)
                {
                    if(positive_preconds.test(i) || negative_preconds.test(i))
                    {
                        auto enum_value = magic_enum::enum_cast<E>(i).value();
                        auto value_name = magic_enum::enum_name(enum_value);
                        
                        std::cout << std::format(" {}{}", 
                                negative_preconds.test(i) ? "-" : "+",
                                value_name) << std::endl;
                    }
                }
            }
        }
    };

    template<typename E>
    requires std::is_enum_v<E>
    using action_list = std::vector<action<E>>;
}; // namespace s2ga

inline void foo()
{
}