Storing lua values in rust

[GeTechG]

Could you help with whether it is possible to safely store data from Lua. I have this test code.

struct LuaEngine<'a> {
    lua: Lua,
    world: Option<Table<'a>>,
}

impl LuaEngine<'_> {
    fn new() -> Self {
        LuaEngine {
            lua: Lua::new(),
            world: None,
        }
    }

    fn load_world(&self) -> Table {
        let chunk = self.lua.load("return { name = \"Mark\" }");
        let table = chunk.eval::<Table>().unwrap();
        table.clone()
    }

    fn ready(&mut self) {
        let table = self.load_world();
        self.world = Some(table);
    }
}

fn main() {
    let mut engine = LuaEngine::new();
    engine.ready();
    println!("{}", engine.world.unwrap().get::<_, mlua::String>("name").unwrap().to_str().unwrap())
}

I'm getting a time-of-life error.

error: lifetime may not live long enough
  --> src/main.rs:23:21
   |
22 |     fn ready(&mut self) {
   |              ---------
   |              |
   |              let's call the lifetime of this reference `'1`
   |              has type `&mut LuaEngine<'2>`
23 |         let table = self.load_world();
   |                     ^^^^^^^^^^^^^^^^^ argument requires that `'1` must outlive `'2`

[khvzak]

There are few options:

1. You can store world table in lua registry (using the Lua::create_registry_value and Lua::registry_value functions)

struct LuaEngine {
    lua: Lua,
    world: Option<RegistryKey>,
}

impl LuaEngine {
    ...

    fn ready(&mut self) {
        let table = self.load_world();
        self.world = Some(self.lua.create_registry_value(table).unwrap());
    }
}

fn main() {
    let mut engine = LuaEngine::new();
    engine.ready();
    let world = engine.lua.registry_value::<Table>(&engine.world.as_ref().unwrap()).unwrap();
    println!("{}", world.get::<_, mlua::String>("name").unwrap().to_str().unwrap())
}

2. Use the new OwnedTable type introduced in mlua v0.9 (beta). It's same as Table but with 'static lifetime.

[GeTechG]

Thank you, I apologize for writing here, there would have been places for questions, like discord, that would have been glorious.