Lua 与C/C++ 交互系列:注冊枚举enum到Lua Code中

在Lua Code中注冊C/C++的枚举很easy,就像注冊全局变量一样。我们使用枚举名称作为命名空间,来避免注冊的枚举发生冲突。注冊的枚举存储在全局环境(线程环境)中。

当在Lua Code中訪问枚举时,通过名称来訪问相应的值。

sample_9.cpp   c++代码例如以下：

//在Lua Code中注冊的enum,为了避免冲突,以名称作为enumTable来存储
enum Week
{
	Monday,
	Tuesday,
	Wednesday,
	Thursday,
	Friday,
	Saturday,
	Sunday,
};
//定义宏用来方便使用设置键值
#define LUA_ENUM(L, val) 
  lua_pushliteral(L, #val); 
  lua_pushnumber(L, val); 
  lua_settable(L, -3)


void register_enum(lua_State* L)
{   //创建一个enumTable,用于存储Enum的全部枚举。通过枚举名称=枚举值
	lua_newtable(L);
	//设置 enumTable["Monday"]=Monday
	LUA_ENUM(L, Monday);
	LUA_ENUM(L, Tuesday);
	LUA_ENUM(L, Wednesday);
	LUA_ENUM(L, Thursday);
	LUA_ENUM(L, Friday);
	LUA_ENUM(L, Saturday);
	LUA_ENUM(L, Sunday);
	//把enumTable存在在_G 全局环境(线程环境)中,以枚举名称作为键
	lua_setglobal(L,"Week");
}
int main(int argc, char *argv[])
{
	lua_State* L = lua_open();
	luaL_openlibs(L);
	register_enum(L);
	luaL_dofile(L, "sample_9.lua");
    lua_close(L);
    return 0;
}

sample_9.lua   Lua Code代码例如以下：

local Week=_G["Week"]
print(Week)
print(Week.Monday)
print(Week.Tuesday)
print(Week.Wednesday)
print(Week.Thursday)
print(Week.Friday)
print(Week.Saturday)
print(Week.Sunday)

输出结果：