Interface Callable

core/src/callable.rs:1054–1070

/// that's the type used throughout the execution engine.
#[async_trait(?Send)]
pub trait Callable {
    /// Returns the metadata for this function.
    ///
    /// The return value takes the form of a reference to force the callable to store the metadata
    /// as a struct field so that calls to this function are guaranteed to be cheap.
    fn metadata(&self) -> Rc<CallableMetadata>;

    /// Executes the callable if it is synchronous.
    fn exec(&self, _scope: Scope<'_>) -> CallResult<()> {
        unimplemented!("Must be implemented for !is_async callables")
    }

    /// Executes the callable if it is asynchronous.
    async fn async_exec(&self, _scope: Scope<'_>) -> CallResult<()> {
        unimplemented!("Must be implemented for is_async callables")
    }
}