Merge pull request 'doc: Adjust code layout and rendering display.' (#1) from kinoshitakenta/event_transformer:main into main

Reviewed-on: http://192.168.29.157:3000/bkinnightskytw/event_transformer/pulls/1

README.md

@@ -2,9 +2,71 @@
 
 Simple utility lib to be interface of event system and simplify transform between different evet lib.
 
-> deprecated, it seems impossible.
+Current implementation require you to define(override) all the event specific dispatch function. If implement lack, you won't pass though compiler.
 
-It seems dynamic reflection is necessary for implementation, but C++ have no this feature.
+> The original goal of this project is ability to override all event behavior by 1 meta function.
+>
+> However, it seems dynamic reflection is necessary for implementation, but C++ have no this feature therefore impossible to achieve.
+
+```cpp
+#include <event_transformer.h>
+#include <so_5/all.hpp>
+
+struct AEvent
+{
+  double speed; // parameter of event
+};
+
+struct BEvent
+{};
+
+/**
+ * @brief
+ * as an interface for fake module process
+ */
+class Fake_module_process_ev : virtual public EventList<AEvent, BEvent>
+{}; // end of Fake_module_process_ev
+
+/**
+ * @brief
+ * real implement
+ */
+// template<typename Functor>
+class So5_fake_module_process_ev : virtual public Fake_module_process_ev
+{
+  so_5::mbox_t target;
+
+public:
+  So5_fake_module_process_ev(so_5::mbox_t target_) : target(target_)
+  {
+  }
+
+  void dispatch(const AEvent& evt) override
+  {
+    cout << "handling AEvent" << endl;
+    so_5::send<AEvent>(target, evt);
+  }
+
+  void dispatch(const BEvent& evt) override
+  {
+    cout << "handling BEvent" << endl;
+    so_5::send<BEvent>(target, evt);
+  }
+};
+
+void fake_module_process(Fake_module_process_ev* evt_li_ptr)
+{
+  // ...
+  dispatch(evt_li_ptr, a_ev);
+  // ...
+}
+```
+
+## build
+
+```bash
+conan build . --build=missing
+```
 
 ## ref
 

conanfile.py

@@ -32,10 +32,10 @@ class event_transformerRecipe(ConanFile):
         # test
         self.test_requires("gtest/[~1.13]")
         self.test_requires("sobjectizer/[~5.8]")
-        self.test_requires("eventpp/[~0.1]")
-        self.test_requires("sigslot/[~1.2]")
-        self.test_requires("caf/[~0.19]")
-        self.test_requires("spdlog/[~1.13]")
+        # self.test_requires("eventpp/[~0.1]")
+        # self.test_requires("sigslot/[~1.2]")
+        # self.test_requires("caf/[~0.19]")
+        # self.test_requires("spdlog/[~1.13]")
 
     def validate(self):
         check_min_cppstd(self, "17")

doc/event_intf_impl_draft.md

@@ -155,4 +155,4 @@ std::any 也可以做到？ [std any use case](https://zh-blog.logan.tw/2021/10/
 > 另外沒有exception 也能用 -fno-exception
 
 以上這些鬼方法，implement 後，應該要藏在最底層的 base class，user 才能直接用，叫user implement 根本要死。但是一放在底層又變ambiguous。要把pointer cast 回它的最底層，才能正確的呼叫使用 map 的 dispatch function。原lib 也有 ` static_cast<EventListener<Event>*>(listener)->onEvent(evt);`。這就顯示出了，map based implement 方法和 inherit based 方法本來就不同，如何合併? 而且本來的inherit implement 就需要一個helper 去幫call。
-可能的方法是，要有 helper class，先在最底層的function，找看看map 有沒有已經存值，沒有了話就 static cast 到對應的type，並且calling。
+可能的方法是，要有 helper class，先在最底層的function，找看看map 有沒有已經存值，沒有了話就 static cast 到對應的type，並且calling。

include/event_transformer.h

@@ -1,90 +1,41 @@
 #pragma once
 
-#include <any>
-#include <functional>
-#include <map>
-#include <typeindex>
-#include <typeinfo>
+using namespace std;
 
-/**
- * @details
- * variadic template + template specialization
- */
 template<class... EventTypes>
-class EventList
-{
-  // no function here will be expose to outer.
-  //  void hello()
-  //  {
-  //    printf("hello");
-  //  }
-};
+class EventList;
 
-/**
- * base of EventList
- */
 template<>
 class EventList<>
 {
 public:
   template<typename EvntLists, typename EVT>
   friend void dispatch(EvntLists* evnt_list_ptr, EVT evt);
-
-  /**
-   * @todo create templated setting functor meta function.
-   */
-  template<typename EvntLists, template<typename Ty> class FunctorT, typename EVT>
-  friend void set_meta(EvntLists* evnt_list_ptr);
-
-  // protected:
-  // std::optional
-  std::map<std::type_index, std::any> fmap;
+  template<typename EvntLists, typename EVT>
+  friend void dispatch(EvntLists evnt_list, EVT evt);
 };
 
-// class Dispatcher
-// {
-//   Dispatcher(Event)
-// };
 template<typename EvntLists, typename EVT>
 void
 dispatch(EvntLists* evnt_list_ptr, EVT evt)
 {
-  auto base = static_cast<EventList<>*>(evnt_list_ptr); //->dispatch(evt);
-  auto any_func = base->fmap.at(std::type_index(typeid(EVT)));
-  if (any_func.has_value()) {
-    auto func = std::any_cast<std::function<void(EVT&)>>(any_func);
-    func(evt); // dispatch
-    return;
-  }
-  // else, call its own private dispatch function.
-  dynamic_cast<EventList<EVT>*>(evnt_list_ptr)->dispatch(evt); // error: 'EventList<>' is not polymorphic, so I need to
-  // create seperate func.
+  static_cast<EventList<EVT>*>(evnt_list_ptr)->dispatch(evt);
 }
-template<typename EvntLists, template<typename Ty> class FunctorT, typename EVT>
+template<typename EvntLists, typename EVT>
 void
-set_meta(EvntLists* evnt_list_ptr)
+dispatch(EvntLists evnt_list, EVT evt)
 {
-  printf("set meta called\n");
-  auto base = static_cast<EventList<>*>(evnt_list_ptr);
-  base->fmap.at(std::type_index(typeid(EVT))) = FunctorT<EVT>();
+  static_cast<EventList<EVT>&>(evnt_list).dispatch(evt);
 }
 
 /**
- * The second event list, connect between event and base
  * @todo addition type but without trigger ambiguous error.
  */
 template<class Event>
 class EventList<Event> : public virtual EventList<>
 {
 public:
-  EventList<Event>()
-  {
-    printf("normal constructor called\n");
-    fmap.insert(std::pair<std::type_index, std::any>(std::type_index(typeid(Event)), std::any()));
-    // auto any_func = fmap.at(std::type_index(typeid(Event)));
-    // printf("any val:%d\n", any_func.has_value());
-  }
-  virtual void dispatch(const Event&){}; //=0
+  virtual void dispatch(const Event&) = 0;
   // virtual void dispatch(Event&)
   // {
   //   cout << "default cb\n";
@@ -95,41 +46,9 @@ public:
   // };
 };
 
-/**
- * intermediate, and hierachy
- */
+
 template<class Event, class... Others>
 class EventList<Event, Others...>
   : public EventList<Event>
   , public EventList<Others...>
-{
-  // EventList<Event, Others...>()
-  // {
-  //   printf("intermediate constructor called\n");
-  // }
-};
-
-/************************************************/
-
-template<template<typename Event> class FunctorT, class Event>
-class EventList<FunctorT<Event>, Event> : public virtual EventList<>
-{
-public:
-  EventList<FunctorT<Event>, Event>()
-  {
-    printf("constructor with functor\n");
-    set_meta<EventList<FunctorT<Event>, Event>, FunctorT, Event>(this);
-  }
-};
-
-template<template<typename Ty> class FunctorT, class Event, class... Others>
-class EventList<FunctorT<Event>, Event, Others...>
-  : public EventList<FunctorT<Event>, Event>
-  , public EventList<Others...>
-{
-public:
-  EventList<FunctorT<Event>, Event, Others...>()
-  {
-    printf("outer, constructor with functor\n");
-  }
-};
+{};

tests/test_event_basic.cpp

@@ -21,7 +21,6 @@ using namespace ::testing;
 
 /**
  * original required by `events` lib
- * Primary template.
  */
 class BaseEvent
 {};
@@ -58,9 +57,6 @@ class Foo_pp : public Foo
 
 public:
   // for c++ 17
-  /**
-   * if cast back to Foo, template function will disapear.
-   */
   template<typename EVT>
   void dispatch(EVT evt)
   {
@@ -84,6 +80,7 @@ TEST_F(Evt_trans_test, create_test)
   // static_cast<EventList<AEvent>>(foo).dispatch(a_ev);
   // static_cast<Foo>(foo).dispatch(a_ev);
   static_cast<EventList<AEvent>&>(foo).dispatch(a_ev);
+  dispatch(foo, a_ev);
   static_cast<EventList<BEvent>&>(foo).dispatch(b_ev);
   // foo.dispatch(a_ev);
   foo.dispatch(std::ref(a_ev));
@@ -101,50 +98,46 @@ TEST_F(Evt_trans_test, create_test)
 #include <typeinfo>
 
 /**
- * @details
- * I want this be interface only.
- * @todo require a dynamic map to map from rtti typeinfo to coresponding function。
+ * @brief
+ * as an interface for fake module process
  */
 class Fake_module_process_ev : virtual public EventList<AEvent, BEvent>
-{}; // Fake_module_process_ev
+{}; // end of Fake_module_process_ev
 
 /**
  * 用friend 會變成 `dispatch(foo, a_event);` 而非 `foo.dispatch(a_event);`
  */
 
 /**
- * I wan't this be implement.
- * 模板派生类
+ * @brief
+ * real implement
  */
 // template<typename Functor>
 class So5_fake_module_process_ev : virtual public Fake_module_process_ev
 {
-  using EventList<AEvent>::dispatch; // to disable warning
-
   so_5::mbox_t target;
 
 public:
   So5_fake_module_process_ev(so_5::mbox_t target_)
     : target(target_)
   {
-    using namespace std;
-    // iterate over all the inherit class and generate function from functor.
-    //
-    std::function<void(AEvent&)> func = [this](AEvent& evt) -> void {
-      // so_5::send<AEvent>(target, evt.speed); //both work, but this isn't
-      so_5::send<AEvent>(target, evt);
-    };
-    fmap[type_index(typeid(AEvent))] = std::any(func);
-    // Functor<>;
   }
+
+  void dispatch(const AEvent& evt) override
+  {
+    cout << "handling AEvent" << endl;
+    so_5::send<AEvent>(target, evt);
+  }
+
   void dispatch(const BEvent& evt) override
   {
-    std::cout << "So5_fake is handling BEvent" << endl;
+    cout << "handling BEvent" << endl;
+    so_5::send<BEvent>(target, evt);
   }
 };
 
 /**
- * simulate module process which require event interface but hide implement.
+ * simulate module process which require event interface
  */
 void
 fake_module_process(Fake_module_process_ev* evt_li_ptr)
@@ -153,13 +146,9 @@ fake_module_process(Fake_module_process_ev* evt_li_ptr)
   std::cout << "fake module called\n";
   std::this_thread::sleep_for(std::chrono::milliseconds(100));
   const AEvent a_ev = AEvent{ .speed = 5.0 };
-  // static_cast<EventList<>*>(evt_li_ptr)->dispatch(a_ev);
-  // static_cast<EventList<>*>(evt_li_ptr)->dispatch(a_ev);
-  // evt_li_ptr->ev_dispatch(a_ev);
-  // static_cast<EventList<decltype(a_ev)>&>(*evt_li_ptr).dispatch(a_ev);
+  // evt_li_ptr->dispatch(std::ref(a_ev));
+  // static_cast<EventList<AEvent>&>(*evt_li_ptr).dispatch(a_ev);
   dispatch(evt_li_ptr, a_ev);
-  const BEvent b_ev = BEvent();
-  dispatch(evt_li_ptr, b_ev);
   std::cout << "fake module exist\n";
   //
 }
@@ -169,7 +158,7 @@ class pinger final : public so_5::agent_t
 
   void on_pong(mhood_t<AEvent> cmd)
   {
-    std::cout << "actor pinger: received a A event, speed: " << cmd->speed << ".\n";
+    std::cout << "actor pinger: received a A event\n";
   }
 
 public:
@@ -208,31 +197,4 @@ TEST_F(Evt_trans_test, so5_fake_module_test)
     env.stop();
   }); // end of so5 launch
 }
-
-/********************************************************************************************************/
-template<typename Evt>
-class Test
-{
-public:
-  void operator()(void)
-  {
-    cout << "empty test\n";
-  };
-};
-
-class Functor_fake_module_process_ev : virtual public Fake_module_process_ev
-{
-public:
-  Functor_fake_module_process_ev()
-  {
-    EventList<Test<AEvent>, AEvent, BEvent>(); //.fmap
-  };
-};
-
-
-TEST(testCase, functor_test)
-{
-  auto t = Functor_fake_module_process_ev();
-}
-
 }