Refactor to remove dependency of DrivenEngine on World

luprex/cpp/core/lpxclient.cpp

@@ -11,6 +11,8 @@
 
 class LpxClient : public DrivenEngine {
 public:
+    EngineWrapper *wrapper_;
+    std::unique_ptr<World> world_;
     InvocationQueue unack_;
     SharedChannel channel_;
     PrintChanneler print_channeler_;
@@ -18,19 +20,22 @@ public:
     lua_State *lua_syntax_checker_;
 
 public:
-    LpxClient() {
+    LpxClient(EngineWrapper *w) : wrapper_(w) {
         lua_syntax_checker_ = LuaCoreStack::newstate(eng::l_alloc);
 
         set_initial_state_standalone();
     }
 
     ~LpxClient() {
+        unexpose_world_to_driver(wrapper_);
         lua_close(lua_syntax_checker_);
     }
 
     void set_initial_state_connect(const eng::string &hostspec) {
         // Create the world model.
+        unexpose_world_to_driver(wrapper_);
         world_.reset(new World(WORLD_TYPE_PREDICTIVE));
+        world_->expose_world_to_driver(wrapper_);
 
         // Create the communication channel.
         channel_ = new_outgoing_channel(hostspec);
@@ -57,7 +62,9 @@ public:
 
     void set_initial_state_standalone() {
         // Create the world model.
+        unexpose_world_to_driver(wrapper_);
         world_.reset(new World(WORLD_TYPE_MASTER));
+        world_->expose_world_to_driver(wrapper_);
 
         // Make sure the channel is empty.
         channel_.reset();