Trait UserDataFields

pub trait UserDataFields<T> {
    // Required methods
    fn add_field<V>(&mut self, name: impl ToString, value: V)
       where V: IntoLua + 'static;
    fn add_field_method_get<M, R>(&mut self, name: impl ToString, method: M)
       where M: Fn(&Lua, &T) -> Result<R> + MaybeSend + 'static,
             R: IntoLua;
    fn add_field_method_set<M, A>(&mut self, name: impl ToString, method: M)
       where M: FnMut(&Lua, &mut T, A) -> Result<()> + MaybeSend + 'static,
             A: FromLua;
    fn add_field_function_get<F, R>(&mut self, name: impl ToString, function: F)
       where F: Fn(&Lua, AnyUserData) -> Result<R> + MaybeSend + 'static,
             R: IntoLua;
    fn add_field_function_set<F, A>(&mut self, name: impl ToString, function: F)
       where F: FnMut(&Lua, AnyUserData, A) -> Result<()> + MaybeSend + 'static,
             A: FromLua;
    fn add_meta_field<V>(&mut self, name: impl ToString, value: V)
       where V: IntoLua + 'static;
    fn add_meta_field_with<F, R>(&mut self, name: impl ToString, f: F)
       where F: FnOnce(&Lua) -> Result<R> + 'static,
             R: IntoLua;
}

Field registry for UserData implementors.

Required Methods

fn add_field<V>(&mut self, name: impl ToString, value: V)

where V: IntoLua + 'static,

Add a static field to the UserData.

Static fields are implemented by updating the __index metamethod and returning the accessed field. This allows them to be used with the expected userdata.field syntax.

Static fields are usually shared between all instances of the UserData of the same type.

If add_meta_method is used to set the __index metamethod, it will be used as a fall-back if no regular field or method are found.

fn add_field_method_get<M, R>(&mut self, name: impl ToString, method: M)

where M: Fn(&Lua, &T) -> Result<R> + MaybeSend + 'static, R: IntoLua,

Add a regular field getter as a method which accepts a &T as the parameter.

Regular field getters are implemented by overriding the __index metamethod and returning the accessed field. This allows them to be used with the expected userdata.field syntax.

If add_meta_method is used to set the __index metamethod, the __index metamethod will be used as a fall-back if no regular field or method are found.

fn add_field_method_set<M, A>(&mut self, name: impl ToString, method: M)

where M: FnMut(&Lua, &mut T, A) -> Result<()> + MaybeSend + 'static, A: FromLua,

Add a regular field setter as a method which accepts a &mut T as the first parameter.

Regular field setters are implemented by overriding the __newindex metamethod and setting the accessed field. This allows them to be used with the expected userdata.field = value syntax.

If add_meta_method is used to set the __newindex metamethod, the __newindex metamethod will be used as a fall-back if no regular field is found.

fn add_field_function_get<F, R>(&mut self, name: impl ToString, function: F)

where F: Fn(&Lua, AnyUserData) -> Result<R> + MaybeSend + 'static, R: IntoLua,

Add a regular field getter as a function which accepts a generic AnyUserData of type T argument.

Prefer to use add_field_method_get as it is easier to use.

fn add_field_function_set<F, A>(&mut self, name: impl ToString, function: F)

where F: FnMut(&Lua, AnyUserData, A) -> Result<()> + MaybeSend + 'static, A: FromLua,

Add a regular field setter as a function which accepts a generic AnyUserData of type T first argument.

Prefer to use add_field_method_set as it is easier to use.

fn add_meta_field<V>(&mut self, name: impl ToString, value: V)

where V: IntoLua + 'static,

Add a metatable field.

This will initialize the metatable field with value on UserData creation.

Note

mlua will trigger an error on an attempt to define a protected metamethod, like __gc or __metatable.

fn add_meta_field_with<F, R>(&mut self, name: impl ToString, f: F)

where F: FnOnce(&Lua) -> Result<R> + 'static, R: IntoLua,

Add a metatable field computed from f.

This will initialize the metatable field from f on UserData creation.

Note

mlua will trigger an error on an attempt to define a protected metamethod, like __gc or __metatable.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<T: 'static> UserDataFields<T> for UserDataRegistry<T>