struct Monster {
 Object proto;
 int hit_points;
};
typedef struct Monster Monster;
int Monster_attack(void *self, int damage);
int Monster_init(void *self);
struct Room {
 Object proto;
 Monster *bad_guy;
 struct Room *north;
 struct Room *south;
 struct Room *east;
 struct Room *west;
};
typedef struct Room Room;
void *Room_move(void *self, Direction direction);
int Room_attack(void *self, int damage);
int Room_init(void *self);
struct Map {
 Object proto;
 Room *start;
 Room *location;
};
typedef struct Map Map;
void *Map_move(void *self, Direction direction);
int Map_attack(void *self, int damage);
int Map_init(void *self);