It is possible now to store data in the Lua AI engine...

...and the data persists between save/load routines // Needs slight
refactoring, use at your own risk

data/ai/scenarios/scenario-lua-ai.cfg

@@ -103,7 +103,12 @@ Gs^Fp       , Gs^Fp       , Wwf         , Wwf         , Mm          , Rd
 	patrol_bilbo = patrol_gen("Bilbo", {{x=2, y=3}, {x=3, y=2}}).exec
 	patrol_sally = patrol_gen("Sally", {{x=5, y=7}, {x=7, y=5}}).exec
 	patrol_eval_rark = ptrl.eval
-	-- End of patrol function //  patrol_gen(ai, "Rark", {{x=14, y=7}, {x=15, y=7}, {x=15, y=8}, {x=14, y=8}}) 
+	-- End of patrol function //  patrol_gen(ai, "Rark", {{x=14, y=7}, {x=15, y=7}, {x=15, y=8}, {x=14, y=8}})
+	
+	function persistance_check()
+		ai.data["pers"] = 182 -- we just set a variable to some value
+		ai.data["stringg"] = " = it works"
+	end
 >>
 [/lua]
 [/event]
@@ -156,7 +161,15 @@ Gs^Fp       , Gs^Fp       , Wwf         , Wwf         , Mm          , Rd
 [event]
 	name=side 2 turn 1
 	first_time_only=yes
-	{MODIFY_AI_DELETE_CANDIDATE_ACTION 2 ca_loop firstca}	
+	{MODIFY_AI_DELETE_CANDIDATE_ACTION 2 ca_loop firstca}
+[/event]
+
+[event]
+	name=side 2 turn 2
+	first_time_only=yes
+	[lua]
+		code = << persistance_check() >>
+	[/lua]
 [/event]
 
     [side]
@@ -290,6 +303,7 @@ Gs^Fp       , Gs^Fp       , Wwf         , Wwf         , Mm          , Rd
                 code= <<
 --! ==============================================================
 ai = ...
+ai.data = {} -- @note: this shouldn't be here
 
 local my_ai = { }
 
@@ -298,8 +312,10 @@ local my_ai = { }
 local ai_stdlib = wesnoth.require('ai/lua/stdlib.lua');
 ai_stdlib.init(ai)
 
+
 function my_ai:stage_hello()
        wesnoth.message('hello from stage!')
+       wesnoth.message('PERSISTANCE: ' .. tostring(ai.data["pers"]) .. ai.data["stringg"])
 end
 
 function my_ai:candidate_action_evaluation_hello()

src/ai/composite/engine_lua.cpp

@@ -187,6 +187,9 @@ engine_lua::engine_lua( readonly_context &context, const config &cfg )
 		cfg["code"].str().c_str(), this))
 {
 	name_ = "lua";
+	
+	config data(cfg.child_or_empty("data"));
+	lua_ai_context_->set_persistent_data(data);
 }
 
 
@@ -272,8 +275,14 @@ void engine_lua::set_ai_context(ai_context * /*context*/)
 config engine_lua::to_config() const
 {
 	config cfg = engine::to_config();
+	
 	cfg["id"] = get_id();
 	cfg["code"] = this->code_;
+	
+	config data = config();
+	lua_ai_context_->get_persistent_data(data);
+	cfg.add_child("data") = data;
+	
 	return cfg;
 }
 

src/ai/lua/core.cpp

@@ -65,6 +65,27 @@ void lua_ai_context::init(lua_State *L)
 	lua_rawset(L, LUA_REGISTRYINDEX);
 }
 
+void lua_ai_context::get_persistent_data(config &cfg) const
+{
+	int top = lua_gettop(L);
+	
+	lua_getglobal(L, "ai");
+	lua_getfield(L, -1, "data");
+	luaW_toconfig(L, -1, cfg);
+	
+	lua_settop(L, top);
+}
+
+void lua_ai_context::set_persistent_data(const config &cfg)
+{
+	int top = lua_gettop(L);
+	
+	lua_getglobal(L, "ai");
+	luaW_pushconfig(L, cfg);
+	lua_setfield(L, -2, "data");
+	
+	lua_settop(L, top);
+}
 static ai::engine_lua &get_engine(lua_State *L)
 {
 	return *((ai::engine_lua*)lua_touserdata(L, lua_upvalueindex(1)));

src/ai/lua/core.hpp

@@ -52,6 +52,8 @@ public:
 	{
 	}
 	void load();
+	void get_persistent_data(config &) const;
+	void set_persistent_data(const config &);
 	static void init(lua_State *L);
 	friend class ::LuaKernel;
 };