Trait MetaObjectProtocol 

pub trait MetaObjectProtocol: Send + Sync {
    // Required methods
    fn raw_get(
        &self,
        cx: &mut Cx,
        value: &Value,
        key: &Value,
    ) -> Result<Option<Value>>;
    fn get_meta(
        &self,
        cx: &mut Cx,
        value: &Value,
        slot: &Symbol,
    ) -> Result<Option<Value>>;

    // Provided method
    fn apply_meta(
        &self,
        cx: &mut Cx,
        _receiver: &Value,
        key: &Value,
        _index_slot: &Symbol,
        meta_value: &Value,
    ) -> Result<Option<Value>> { ... }
}

Language-neutral slot lookup for values with metadata-driven behavior.

Implementations provide raw indexed access plus a named meta-slot lookup. The slot names are supplied by language crates or other callers, so this protocol can model metatables, prototype parents, method dictionaries, and similar object layers without baking any one language’s names into dispatch.

Required Methods

fn raw_get( &self, cx: &mut Cx, value: &Value, key: &Value, ) -> Result<Option<Value>>

Returns a raw indexed value before consulting any metaobject fallback.

fn get_meta( &self, cx: &mut Cx, value: &Value, slot: &Symbol, ) -> Result<Option<Value>>

Returns the meta value installed under slot for value, if present.

Provided Methods

fn apply_meta( &self, cx: &mut Cx, _receiver: &Value, key: &Value, _index_slot: &Symbol, meta_value: &Value, ) -> Result<Option<Value>>

Applies a meta value to the original indexed read.

The default treats the meta value as another indexable object and looks up key on it. Prototype languages can override this to recurse through parent objects, while function-backed systems can override it to invoke or otherwise interpret a callable meta value.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors