action.hpp

//Copyright Florian Goujeon 2021 - 2025.
//Distributed under the Boost Software License, Version 1.0.
//(See accompanying file LICENSE or copy at
//https://www.boost.org/LICENSE_1_0.txt)
//Official repository: https://github.com/fgoujeon/maki

 
#ifndef MAKI_ACTION_HPP
#define MAKI_ACTION_HPP
 
#include "detail/signature_macros.hpp"
#include "detail/call.hpp"
#include "null.hpp"
 
namespace maki
{

enum class action_signature: char
{
    v,

    c,

    cm,

    cme,

    ce,

    m,

    me,

    e,
};

template<action_signature Sig, class Callable>
struct action
{
    static constexpr action_signature signature = Sig;
    Callable callable;
};
 
#define MAKI_DETAIL_X(name) /*NOLINT(cppcoreguidelines-macro-usage)*/ \
 \
    template<class Callable> \
    constexpr action<action_signature::name, Callable> action_##name(const Callable& callable) \
    { \
        return {callable}; \
    }
MAKI_DETAIL_ACTION_SIGNATURES
#undef MAKI_DETAIL_X
 
namespace detail
{
    inline constexpr auto null_action = action_v([]{});
 
    template<action_signature Sig, class Callable>
    constexpr const auto& to_action(const action<Sig, Callable>& act)
    {
        return act;
    }
 
    constexpr const auto& to_action(null_t /*ignored*/)
    {
        return null_action;
    }
 
    template<class T>
    struct is_action
    {
        static constexpr auto value = false;
    };
 
    template<action_signature Sig, class Callable>
    struct is_action<action<Sig, Callable>>
    {
        static constexpr auto value = true;
    };
 
    template<class T>
    constexpr bool is_action_v = is_action<T>::value;
 
    template
    <
        class Action,
        class Context,
        class Machine,
        class Event
    >
    void call_action
    (
        const Action& act,
        Context& ctx,
        Machine& mach,
        const Event& event
    )
    {
        call_callable<action_signature, Action::signature>
        (
            act.callable,
            ctx,
            mach,
            event
        );
    }
}
 
} //namespace
 
#endif