MudEngine Part 7: Save & Load

You just added persistent game state to the MUD engine!

What we achieved:

• Data-driven world — the full 9-room grid is defined in game.toml, editable without recompiling
• Server-side persistence — player positions are saved to disk on every join, move, and leave
• Client-server synchronisation — room data is sent from the server to the client in the initial State message, eliminating the hardcoded statics
• Save/load architecture — load_game_state() at startup, save_game_state() after every mutation, can_move() for movement validation from loaded data
• Cleanup — the old ROOM_NAMES, ROOM_DESCS, and EXITS statics are gone; the game is fully data-driven

Architecture recap

game.toml ──read──▶  LazyLock ──▶ GameState { rooms, players }
                           │
              ┌────────────┼────────────┐
              ▼            ▼            ▼
         Player join   Player move   Player leave
              │            │            │
              └────────────┼────────────┘
                           ▼
                    save_game_state()
                           │
                           ▼
                    game.toml (updated)

What's next?

The dungeon keeps growing! Future parts could explore:

• SQLite database — replace game.toml with sqlx + SQLite for concurrent read/write access
• Room state — locked doors, dark rooms that need a torch, writable signs
• Inventory — items the player can pick up, carry between rooms, and drop
• Chat — add a chat panel where players can send messages to each other
• Monsters & combat — NPCs roaming the world, attack commands, health bars
• Editor UI — an admin panel to edit room data from the browser

The MUD persists! 🏰💾