fsm_generator.h

/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Copyright(c) 2017 John Wellbelove
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files(the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions :
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
******************************************************************************/
 
/*[[[cog
import cog
cog.outl("#if 0")
]]]*/
/*[[[end]]]*/
#error THIS HEADER IS A GENERATOR. DO NOT INCLUDE.
/*[[[cog
import cog
cog.outl("#endif")
]]]*/
/*[[[end]]]*/
 
/*[[[cog
import cog
cog.outl("//***************************************************************************")
cog.outl("// THIS FILE HAS BEEN AUTO GENERATED. DO NOT EDIT THIS FILE.")
cog.outl("//***************************************************************************")
]]]*/
/*[[[end]]]*/
 
//***************************************************************************
// To generate to header file, run this at the command line.
// Note: You will need Python and COG installed.
//
// cog -d -e -ofsm.h -DHandlers=<n> fsm_generator.h
// Where <n> is the number of messages to support.
//
// e.g.
// To generate handlers for up to 16 events...
// cog -d -e -ofsm.h -DHandlers=16 fsm_generator.h
//
// See generate.bat
//***************************************************************************
 
#ifndef ETL_FSM_INCLUDED
#define ETL_FSM_INCLUDED
 
#include "platform.h"
#include "array.h"
#include "nullptr.h"
#include "error_handler.h"
#include "exception.h"
#include "user_type.h"
#include "message_router.h"
#include "integral_limits.h"
#include "largest.h"
#if ETL_USING_CPP11
  #include "tuple.h"
#endif
 
#include <stdint.h>
 
#include "private/minmax_push.h"
 
namespace etl
{
  class fsm;
  class hfsm;
 
#if !defined(ETL_FSM_STATE_ID_TYPE)
  typedef uint_least8_t fsm_state_id_t;
#else
  typedef ETL_FSM_STATE_ID_TYPE fsm_state_id_t;
#endif
 
  // For internal FSM use.
  typedef typename etl::larger_type<etl::message_id_t>::type fsm_internal_id_t;
 
#if ETL_USING_CPP17 && !defined(ETL_FSM_FORCE_CPP03_IMPLEMENTATION) // For C++17 and above
  template <typename, typename, etl::fsm_state_id_t, typename...>
  class fsm_state;
#else
  /*[[[cog
  import cog
  cog.outl("template <typename, typename, etl::fsm_state_id_t,")
  cog.out("          ")
  for n in range(1, int(Handlers)):
    cog.out("typename, ")
    if n % 4 == 0:
        cog.outl("")
        cog.out("          ")
  cog.outl("typename>")
  cog.outl("class fsm_state;")
  ]]]*/
  /*[[[end]]]*/
#endif
 
  //***************************************************************************
  //***************************************************************************
  class fsm_exception : public etl::exception
  {
  public:
 
    fsm_exception(string_type reason_, string_type file_name_, numeric_type line_number_)
      : etl::exception(reason_, file_name_, line_number_)
    {
    }
  };
 
  //***************************************************************************
  //***************************************************************************
  class fsm_null_state_exception : public etl::fsm_exception
  {
  public:
 
    fsm_null_state_exception(string_type file_name_, numeric_type line_number_)
      : etl::fsm_exception(ETL_ERROR_TEXT("fsm:null state", ETL_FSM_FILE_ID"A"), file_name_, line_number_)
    {
    }
  };
 
  //***************************************************************************
  //***************************************************************************
  class fsm_state_id_exception : public etl::fsm_exception
  {
  public:
 
    fsm_state_id_exception(string_type file_name_, numeric_type line_number_)
      : etl::fsm_exception(ETL_ERROR_TEXT("fsm:state id", ETL_FSM_FILE_ID"B"), file_name_, line_number_)
    {
    }
  };
 
  //***************************************************************************
  //***************************************************************************
  class fsm_state_list_exception : public etl::fsm_exception
  {
  public:
 
    fsm_state_list_exception(string_type file_name_, numeric_type line_number_)
      : etl::fsm_exception(ETL_ERROR_TEXT("fsm:state list", ETL_FSM_FILE_ID"C"), file_name_, line_number_)
    {
    }
  };
 
  //***************************************************************************
  //***************************************************************************
  class fsm_state_list_order_exception : public etl::fsm_exception
  {
  public:
 
    fsm_state_list_order_exception(string_type file_name_, numeric_type line_number_)
      : etl::fsm_exception(ETL_ERROR_TEXT("fsm:state list order", ETL_FSM_FILE_ID"D"), file_name_, line_number_)
    {
    }
  };
 
  //***************************************************************************
  //***************************************************************************
  class fsm_not_started : public etl::fsm_exception
  {
  public:
    fsm_not_started(string_type file_name_, numeric_type line_number_)
      : etl::fsm_exception(ETL_ERROR_TEXT("fsm:not started", ETL_FSM_FILE_ID"F"), file_name_, line_number_)
    {
    }
  };
 
  //***************************************************************************
  //***************************************************************************
  class fsm_reentrant_transition_forbidden : public etl::fsm_exception
  {
  public:
    fsm_reentrant_transition_forbidden(string_type file_name_, numeric_type line_number_)
      : etl::fsm_exception(ETL_ERROR_TEXT("fsm:reentrant calls to start/receive/etc. forbidden", ETL_FSM_FILE_ID"G"), file_name_, line_number_)
    {
    }
  };
 
  namespace private_fsm
  {
    template <typename T = void>
    class ifsm_state_helper
    {
    public:
 
      // Pass this whenever no state change is desired.
      // The highest unsigned value of fsm_state_id_t.
      static ETL_CONSTANT fsm_state_id_t No_State_Change = etl::integral_limits<fsm_state_id_t>::max;
      
      // Pass this when this event also needs to be passed to the parent.
      static ETL_CONSTANT fsm_state_id_t Pass_To_Parent = No_State_Change - 1U;
 
      // Pass this when this event should trigger a self transition.
      static ETL_CONSTANT fsm_state_id_t Self_Transition = No_State_Change - 2U;
    };
 
    template <typename T>
    ETL_CONSTANT fsm_state_id_t ifsm_state_helper<T>::No_State_Change;
 
    template <typename T>
    ETL_CONSTANT fsm_state_id_t ifsm_state_helper<T>::Pass_To_Parent;
 
    template <typename T>
    ETL_CONSTANT fsm_state_id_t ifsm_state_helper<T>::Self_Transition;
 
    // Compile-time: TState::ID must equal its index in the type list (0..N-1)
    template <size_t Id, typename...> struct check_ids : etl::true_type 
    {
    };
 
    template <size_t Id, typename TState0, typename... TRest>
    struct check_ids<Id, TState0, TRest...>
      : etl::integral_constant<bool, (TState0::STATE_ID == Id) && private_fsm::check_ids<Id + 1, TRest...>::value> 
    {
    };   
 
    //***************************************************************************
    //***************************************************************************
    class fsm_reentrancy_guard
    {
    public:
      //*******************************************
      //*******************************************
      fsm_reentrancy_guard(bool& transition_guard_flag)
        : is_locked(transition_guard_flag)
      {
        ETL_ASSERT(!is_locked, ETL_ERROR(etl::fsm_reentrant_transition_forbidden));
        is_locked = true;
      }
 
      //*******************************************
      //*******************************************
      ~fsm_reentrancy_guard() ETL_NOEXCEPT
      {
        is_locked = false;
      }
      
    private:
      // Reference to the flag signifying a lock on the state machine.
      bool& is_locked;
      
      // Copy & move semantics disabled since this is a guard.
      fsm_reentrancy_guard(fsm_reentrancy_guard const&) ETL_DELETE;
      fsm_reentrancy_guard& operator= (fsm_reentrancy_guard const&) ETL_DELETE;
#if ETL_USING_CPP11
      fsm_reentrancy_guard(fsm_reentrancy_guard&&) ETL_DELETE;
      fsm_reentrancy_guard& operator= (fsm_reentrancy_guard&&) ETL_DELETE;
#endif
    };
  }
 
  class ifsm_state;
 
#if ETL_USING_CPP11
  //***************************************************************************
  //***************************************************************************
  template <typename... TStates>
  class fsm_state_pack 
  {
  public:
 
    friend class etl::fsm;
 
    ETL_STATIC_ASSERT((private_fsm::check_ids<0, TStates...>::value), "State IDs must be 0..N-1 and in order");
    ETL_STATIC_ASSERT(sizeof...(TStates) > 0, "At least one state is required");
    ETL_STATIC_ASSERT(sizeof...(TStates) < private_fsm::ifsm_state_helper<>::No_State_Change, "State IDs mst be less than ifsm_state::No_State_Change");
 
    //*********************************
    // The number of states.
    //*********************************
    static ETL_CONSTEXPR size_t size()
    {
      return sizeof...(TStates);
    }
 
    //*********************************
    //*********************************
    template <typename TState>
    TState& get() 
    { 
      return etl::get<TState>(storage); 
    }
 
    //*********************************
    //*********************************
    template <typename TState>
    const TState& get() const 
    { 
      return etl::get<TState>(storage); 
    }
 
  private:
 
    //*********************************
    //*********************************
    etl::ifsm_state** get_state_list()
    {
      return &states[0];
    }
 
    etl::tuple<TStates...> storage{};
 
    etl::ifsm_state* states[sizeof...(TStates)]{ &etl::get<TStates>(storage)... };
  };
#endif
 
  //***************************************************************************
  //***************************************************************************
  class ifsm_state : public private_fsm::ifsm_state_helper<>
  {
  public:
 
    friend class etl::fsm;
    friend class etl::hfsm;
 
    using private_fsm::ifsm_state_helper<>::No_State_Change;
    using private_fsm::ifsm_state_helper<>::Pass_To_Parent;
    using private_fsm::ifsm_state_helper<>::Self_Transition;
 
#if ETL_USING_CPP17 && !defined(ETL_FSM_FORCE_CPP03_IMPLEMENTATION) // For C++17 and above
    template <typename, typename, etl::fsm_state_id_t, typename...>
    friend class fsm_state;
#else
    /*[[[cog
    import cog
    cog.outl("  template <typename, typename, etl::fsm_state_id_t,")
    cog.out("            ")
    for n in range(1, int(Handlers)):
      cog.out("typename, ")
      if n % 4 == 0:
          cog.outl("")
          cog.out("            ")
    cog.outl("typename>")
    ]]]*/
    /*[[[end]]]*/
    friend class etl::fsm_state;
#endif
 
    //*******************************************
    //*******************************************
    etl::fsm_state_id_t get_state_id() const
    {
      return state_id;
    }
 
    //*******************************************
    //*******************************************
    void add_child_state(etl::ifsm_state& state)
    {
      ETL_ASSERT(state.p_parent == ETL_NULLPTR, ETL_ERROR(etl::fsm_null_state_exception));
      state.p_parent = this;
 
      if (p_default_child == ETL_NULLPTR)
      {
        p_default_child = &state;
      }
    }
 
    //*******************************************
    //*******************************************
    template <typename TSize>
    void set_child_states(etl::ifsm_state** state_list, TSize size)
    {
      p_active_child = ETL_NULLPTR;
      p_default_child = ETL_NULLPTR;
 
      for (TSize i = 0; i < size; ++i)
      {
        ETL_ASSERT(state_list[i] != ETL_NULLPTR, ETL_ERROR(etl::fsm_null_state_exception));
        add_child_state(*state_list[i]);
      }
    }
 
  protected:
 
    //*******************************************
    //*******************************************
    ifsm_state(etl::fsm_state_id_t state_id_)
      : state_id(state_id_),
      p_context(ETL_NULLPTR),
      p_parent(ETL_NULLPTR),
      p_active_child(ETL_NULLPTR),
      p_default_child(ETL_NULLPTR)
    {
    }
 
    //*******************************************
    //*******************************************
    virtual ~ifsm_state()
    {
    }
 
    //*******************************************
    etl::fsm& get_fsm_context() const
    {
      return *p_context;
    }
 
  private:
 
    virtual fsm_state_id_t process_event(const etl::imessage& message) = 0;
 
    virtual fsm_state_id_t on_enter_state() { return No_State_Change; } // By default, do nothing.
    virtual void on_exit_state() {}  // By default, do nothing.
 
    //*******************************************
    void set_fsm_context(etl::fsm& context)
    {
      p_context = &context;
    }
 
    // The state id.
    const etl::fsm_state_id_t state_id;
 
    // A pointer to the FSM context.
    etl::fsm* p_context;
 
    // A pointer to the parent.
    ifsm_state* p_parent;
 
    // A pointer to the active child.
    ifsm_state* p_active_child;
 
    // A pointer to the default active child.
    ifsm_state* p_default_child;
 
    // Disabled.
    ifsm_state(const ifsm_state&) ETL_DELETE;
    ifsm_state& operator =(const ifsm_state&) ETL_DELETE;
  };
 
  //***************************************************************************
  //***************************************************************************
  class fsm : public etl::imessage_router
  {
  public:
 
    friend class etl::hfsm;
    using imessage_router::receive;
 
    //*******************************************
    //*******************************************
    fsm(etl::message_router_id_t id)
      : imessage_router(id)
      , p_state(ETL_NULLPTR)
      , state_list(ETL_NULLPTR)
      , number_of_states(0U)
      , is_processing_state_change(false)
    {
    }
 
    //*******************************************
    //*******************************************
    template <typename TSize>
    void set_states(etl::ifsm_state** p_states, TSize size)
    {
      state_list = p_states;
      number_of_states = etl::fsm_state_id_t(size);
 
      ETL_ASSERT(number_of_states > 0, ETL_ERROR(etl::fsm_state_list_exception));
      ETL_ASSERT(number_of_states < ifsm_state::No_State_Change, ETL_ERROR(etl::fsm_state_list_exception));
 
      for (etl::fsm_state_id_t i = 0; i < size; ++i)
      {
        ETL_ASSERT(state_list[i] != ETL_NULLPTR, ETL_ERROR(etl::fsm_null_state_exception));
        ETL_ASSERT(state_list[i]->get_state_id() == i, ETL_ERROR(etl::fsm_state_list_order_exception));
        state_list[i]->set_fsm_context(*this);
      }
    }
 
#if ETL_USING_CPP11
    //*******************************************
    //*******************************************
    template <typename... TStates>
    void set_states(etl::fsm_state_pack<TStates...>& state_pack)
    {
      state_list = state_pack.get_state_list();
      number_of_states = etl::fsm_state_id_t(state_pack.size());
 
      for (etl::fsm_state_id_t i = 0; i < number_of_states; ++i)
      {
        state_list[i]->set_fsm_context(*this);
      }
    }
#endif
 
    //*******************************************
    //*******************************************
    virtual void start(bool call_on_enter_state = true)
    {
      private_fsm::fsm_reentrancy_guard transition_lock(is_processing_state_change);
 
      // Can only be started once.
      if (!is_started())
      {
        p_state = state_list[0];
        ETL_ASSERT(p_state != ETL_NULLPTR, ETL_ERROR(etl::fsm_null_state_exception));
 
        if (call_on_enter_state)
        {
          etl::fsm_state_id_t next_state_id;
          etl::ifsm_state* p_last_state;
 
          do
          {
            p_last_state = p_state;
            next_state_id = p_state->on_enter_state();
            if (next_state_id != ifsm_state::No_State_Change)
            {
              ETL_ASSERT(next_state_id < number_of_states, ETL_ERROR(etl::fsm_state_id_exception));
              p_state = state_list[next_state_id];
            }
          } while (p_last_state != p_state);
        }
      }
    }
 
    //*******************************************
    //*******************************************
    void receive(const etl::imessage& message) ETL_OVERRIDE
    {
      private_fsm::fsm_reentrancy_guard transition_lock(is_processing_state_change);
 
      if (is_started())
      {
        etl::fsm_state_id_t next_state_id = p_state->process_event(message);
 
        process_state_change(next_state_id); 
      }
      else
      {
        ETL_ASSERT_FAIL(ETL_ERROR(etl::fsm_not_started));
      }
    }
 
    //*******************************************
    //*******************************************
    etl::fsm_state_id_t transition_to(etl::fsm_state_id_t new_state_id)
    {
      private_fsm::fsm_reentrancy_guard transition_lock(is_processing_state_change);
 
      if (is_started())
      {
        return process_state_change(new_state_id);
      }
      else
      {
        return ifsm_state::No_State_Change;
      }
    }
 
    using imessage_router::accepts;
 
    //*******************************************
    //*******************************************
    bool accepts(etl::message_id_t) const ETL_OVERRIDE
    {
      return true;
    }
 
    //*******************************************
    //*******************************************
    etl::fsm_state_id_t get_state_id() const
    {
      ETL_ASSERT(p_state != ETL_NULLPTR, ETL_ERROR(etl::fsm_null_state_exception));
      return p_state->get_state_id();
    }
 
    //*******************************************
    //*******************************************
    ifsm_state& get_state()
    {
      ETL_ASSERT(p_state != ETL_NULLPTR, ETL_ERROR(etl::fsm_null_state_exception));
      return *p_state;
    }
 
    //*******************************************
    //*******************************************
    const ifsm_state& get_state() const
    {
      ETL_ASSERT(p_state != ETL_NULLPTR, ETL_ERROR(etl::fsm_null_state_exception));
      return *p_state;
    }
 
    //*******************************************
    //*******************************************
    bool is_started() const
    {
      return p_state != ETL_NULLPTR;
    }
 
    //*******************************************
    //*******************************************
    virtual void reset(bool call_on_exit_state = false)
    {
      private_fsm::fsm_reentrancy_guard transition_lock(is_processing_state_change);
 
      if (is_started() && call_on_exit_state)
      {
        p_state->on_exit_state();
      }
 
      p_state = ETL_NULLPTR;
    }
 
    //********************************************
    ETL_DEPRECATED bool is_null_router() const ETL_OVERRIDE
    {
      return false;
    }
 
    //********************************************
    bool is_producer() const ETL_OVERRIDE
    {
      return true;
    }
 
    //********************************************
    bool is_consumer() const ETL_OVERRIDE
    {
      return true;
    }
 
  private:
 
    //********************************************
    bool have_changed_state(etl::fsm_state_id_t next_state_id) const
    {
      return (next_state_id != p_state->get_state_id()) &&
             (next_state_id != ifsm_state::No_State_Change) &&
             (next_state_id != ifsm_state::Self_Transition);
    }
 
    //********************************************
    bool is_self_transition(etl::fsm_state_id_t next_state_id) const
    {
      return (next_state_id == ifsm_state::Self_Transition);
    }
 
    //*******************************************
    //*******************************************
    virtual etl::fsm_state_id_t process_state_change(etl::fsm_state_id_t next_state_id)
    {
      if (is_self_transition(next_state_id))
      {
        p_state->on_exit_state();
        next_state_id = p_state->on_enter_state();
      }
      
      if (have_changed_state(next_state_id))
      {
        ETL_ASSERT_OR_RETURN_VALUE(next_state_id < number_of_states, ETL_ERROR(etl::fsm_state_id_exception), p_state->get_state_id());
        etl::ifsm_state* p_next_state = state_list[next_state_id];
 
        do
        {
          p_state->on_exit_state();
          p_state = p_next_state;
 
          next_state_id = p_state->on_enter_state();
 
          if (have_changed_state(next_state_id))
          {
            ETL_ASSERT_OR_RETURN_VALUE(next_state_id < number_of_states, ETL_ERROR(etl::fsm_state_id_exception), p_state->get_state_id());
            p_next_state = state_list[next_state_id];
          }
        } while (p_next_state != p_state); // Have we changed state again?
      }
 
      return p_state->get_state_id();
    }
 
    etl::ifsm_state*    p_state;          
    etl::ifsm_state**   state_list;       
    etl::fsm_state_id_t number_of_states; 
    bool is_processing_state_change;      
  };
 
  //*************************************************************************************************
  // For C++17 and above.
  //*************************************************************************************************
#if ETL_USING_CPP17 && !defined(ETL_FSM_FORCE_CPP03_IMPLEMENTATION) // For C++17 and above
  //***************************************************************************
  // The definition for all types.
  //***************************************************************************
  template <typename TContext, typename TDerived, etl::fsm_state_id_t STATE_ID_, typename... TMessageTypes>
  class fsm_state : public ifsm_state
  {
  public:
 
    static ETL_CONSTANT etl::fsm_state_id_t STATE_ID = STATE_ID_;
 
    fsm_state()
      : ifsm_state(STATE_ID)
    {
    }
 
  protected:
 
    ~fsm_state()
    {
    }
 
    TContext& get_fsm_context() const
    {
      return static_cast<TContext&>(ifsm_state::get_fsm_context());
    }
 
  private:
 
    //********************************************
    struct result_t
    {
      bool was_handled;
      etl::fsm_state_id_t state_id;
    };
 
    //********************************************
    etl::fsm_state_id_t process_event(const etl::imessage& message)
    {
      etl::fsm_state_id_t new_state_id;
 
      const bool was_handled = (process_event_type<TMessageTypes>(message, new_state_id) || ...);
 
      if (!was_handled || (new_state_id == Pass_To_Parent))
      {
        new_state_id = (p_parent != nullptr) ? p_parent->process_event(message) : static_cast<TDerived*>(this)->on_event_unknown(message);
      }
 
      return new_state_id;
    }
 
    //********************************************
    template <typename TMessage>
    bool process_event_type(const etl::imessage& msg, etl::fsm_state_id_t& new_state_id)
    {
      if (TMessage::ID == msg.get_message_id())
      {
        new_state_id = static_cast<TDerived*>(this)->on_event(static_cast<const TMessage&>(msg));
        return true;
      }
      else
      {
        return false;
      }
    }
  };
 
  template <typename TContext, typename TDerived, etl::fsm_state_id_t STATE_ID_, typename... TMessageTypes>
  ETL_CONSTANT etl::fsm_state_id_t fsm_state<TContext, TDerived, STATE_ID_, TMessageTypes...>::STATE_ID;
 
#else
//*************************************************************************************************
// For C++14 and below.
//*************************************************************************************************
  /*[[[cog
  import cog
  ################################################
  # The first definition for all of the events.
  ################################################
  cog.outl("//***************************************************************************")
  cog.outl("// The definition for all %s message types." % Handlers)
  cog.outl("//***************************************************************************")
  cog.outl("template <typename TContext, typename TDerived, etl::fsm_state_id_t STATE_ID_, ")
  cog.out("          ")
  for n in range(1, int(Handlers)):
      cog.out("typename T%s = void, " % n)
      if n % 4 == 0:
          cog.outl("")
          cog.out("          ")
  cog.outl("typename T%s = void>" % Handlers)
  cog.outl("class fsm_state : public ifsm_state")
  cog.outl("{")
  cog.outl("public:")
  cog.outl("")
  cog.outl("  static ETL_CONSTANT etl::fsm_state_id_t STATE_ID = STATE_ID_;")
  cog.outl("")
  cog.outl("  fsm_state()")
  cog.outl("    : ifsm_state(STATE_ID)")
  cog.outl("  {")
  cog.outl("  }")
  cog.outl("")
  cog.outl("protected:")
  cog.outl("")
  cog.outl("  ~fsm_state()")
  cog.outl("  {")
  cog.outl("  }")
  cog.outl("")
  cog.outl("  TContext& get_fsm_context() const")
  cog.outl("  {")
  cog.outl("    return static_cast<TContext&>(ifsm_state::get_fsm_context());")
  cog.outl("  }")
  cog.outl("")
  cog.outl("private:")
  cog.outl("")
  cog.outl("  etl::fsm_state_id_t process_event(const etl::imessage& message)")
  cog.outl("  {")
  cog.outl("    etl::fsm_state_id_t new_state_id;")
  cog.outl("    etl::message_id_t event_id = message.get_message_id();")
  cog.outl("")
  cog.outl("    switch (event_id)")
  cog.outl("    {")
  for n in range(1, int(Handlers) + 1):
      cog.out("      case T%d::ID:" % n)
      cog.out(" new_state_id = static_cast<TDerived*>(this)->on_event(static_cast<const T%d&>(message));" % n)
      cog.outl(" break;")
  cog.out("      default:")
  cog.out(" new_state_id = p_parent ? p_parent->process_event(message) : static_cast<TDerived*>(this)->on_event_unknown(message);")
  cog.outl(" break;")
  cog.outl("    }")
  cog.outl("")
  cog.outl("    return (new_state_id != Pass_To_Parent) ? new_state_id : (p_parent ? p_parent->process_event(message) : No_State_Change);")
  cog.outl("  }")
  cog.outl("};")
 
  ####################################
  # All of the other specialisations.
  ####################################
  for n in range(int(Handlers) - 1, 0, -1):
      cog.outl("")
      cog.outl("//***************************************************************************")
      if n == 1:
          cog.outl("// Specialisation for %d message type." % n)
      else:
          cog.outl("// Specialisation for %d message types." % n)
      cog.outl("//***************************************************************************")
      cog.outl("template <typename TContext, typename TDerived, etl::fsm_state_id_t STATE_ID_, ")
      cog.out("          ")
      for t in range(1, n):
          cog.out("typename T%d, " % t)
          if t % 4 == 0:
              cog.outl("")
              cog.out("          ")
      cog.outl("typename T%d>" % n)
      cog.out("class fsm_state<TContext, TDerived, STATE_ID_, ")
      for t in range(1, n + 1):
          cog.out("T%d, " % t)
      if t % 16 == 0:
          cog.outl("")
          cog.out("               ")
      for t in range(n + 1, int(Handlers)):
          cog.out("void, ")
      if t % 16 == 0:
          cog.outl("")
          cog.out("               ")
      cog.outl("void> : public ifsm_state")
      cog.outl("{")
      cog.outl("public:")
      cog.outl("")
      cog.outl("  static ETL_CONSTANT etl::fsm_state_id_t STATE_ID = STATE_ID_;")
      cog.outl("")
      cog.outl("  fsm_state()")
      cog.outl("    : ifsm_state(STATE_ID)")
      cog.outl("  {")
      cog.outl("  }")
      cog.outl("")
      cog.outl("protected:")
      cog.outl("")
      cog.outl("  ~fsm_state()")
      cog.outl("  {")
      cog.outl("  }")
      cog.outl("")
      cog.outl("  TContext& get_fsm_context() const")
      cog.outl("  {")
      cog.outl("    return static_cast<TContext&>(ifsm_state::get_fsm_context());")
      cog.outl("  }")
      cog.outl("")
      cog.outl("private:")
      cog.outl("")
      cog.outl("  etl::fsm_state_id_t process_event(const etl::imessage& message)")
      cog.outl("  {")
      cog.outl("    etl::fsm_state_id_t new_state_id;")
      cog.outl("    etl::message_id_t event_id = message.get_message_id();")
      cog.outl("")
      cog.outl("    switch (event_id)")
      cog.outl("    {")
      for n in range(1, n + 1):
          cog.out("      case T%d::ID:" % n)
          cog.out(" new_state_id = static_cast<TDerived*>(this)->on_event(static_cast<const T%d&>(message));" % n)
          cog.outl(" break;")
      cog.out("      default:")
      cog.out(" new_state_id = p_parent ? p_parent->process_event(message) : static_cast<TDerived*>(this)->on_event_unknown(message);")
      cog.outl(" break;")
      cog.outl("    }")
      cog.outl("")
      cog.outl("    return (new_state_id != Pass_To_Parent) ? new_state_id : (p_parent ? p_parent->process_event(message) : No_State_Change);")
      cog.outl("  }")
      cog.outl("};")
  ####################################
  # Specialisation for zero messages.
  ####################################
  cog.outl("")
  cog.outl("//***************************************************************************")
  cog.outl("// Specialisation for 0 message types.")
  cog.outl("//***************************************************************************")
  cog.outl("template <typename TContext, typename TDerived, etl::fsm_state_id_t STATE_ID_>")
  cog.out("class fsm_state<TContext, TDerived, STATE_ID_, ")
  for t in range(1, int(Handlers)):
      cog.out("void, ")
  if t % 16 == 0:
      cog.outl("")
      cog.out("               ")
  cog.outl("void> : public ifsm_state")
  cog.outl("{")
  cog.outl("public:")
  cog.outl("")
  cog.outl("  static ETL_CONSTANT etl::fsm_state_id_t STATE_ID = STATE_ID_;")
  cog.outl("")
  cog.outl("  fsm_state()")
  cog.outl("    : ifsm_state(STATE_ID)")
  cog.outl("  {")
  cog.outl("  }")
  cog.outl("")
  cog.outl("protected:")
  cog.outl("")
  cog.outl("  ~fsm_state()")
  cog.outl("  {")
  cog.outl("  }")
  cog.outl("")
  cog.outl("  TContext& get_fsm_context() const")
  cog.outl("  {")
  cog.outl("    return static_cast<TContext&>(ifsm_state::get_fsm_context());")
  cog.outl("  }")
  cog.outl("private:")
  cog.outl("")
  cog.outl("  etl::fsm_state_id_t process_event(const etl::imessage& message)")
  cog.outl("  {")
  cog.outl("    return p_parent ? p_parent->process_event(message) : static_cast<TDerived*>(this)->on_event_unknown(message);")
  cog.outl("  }")
  cog.outl("};")
 
  cog.outl("")
  cog.outl("template <typename TContext, typename TDerived, etl::fsm_state_id_t STATE_ID_, ")
  cog.out("          ")
  for n in range(1, int(Handlers)):
      cog.out("typename T%s, " % n)
      if n % 4 == 0:
          cog.outl("")
          cog.out("          ")
  cog.outl("typename T%s>" % Handlers)
  cog.out("ETL_CONSTANT etl::fsm_state_id_t fsm_state<TContext, TDerived, STATE_ID_, ")
  for n in range(1, int(Handlers)):
      cog.out("T%s, " % n)
  cog.outl("T%s>::STATE_ID;" % Handlers)
  ]]]*/
  /*[[[end]]]*/
#endif
}
 
#include "private/minmax_pop.h"
 
#endif