Function message_worker::non_blocking::listen

pub fn listen<Ctx, CtxFactory, Source, Message, HandleMessageFuture, HandleMessageErrorT>(
    source: Source, 
    context_factory: CtxFactory, 
    handle_message: fn(_: Arc<Ctx>, _: Message) -> HandleMessageFuture
) -> JoinHandle<()> where
    Ctx: Send + Sync + 'static,
    CtxFactory: FnOnce() -> Ctx + Send + 'static,
    Source: Stream<Item = Message> + Unpin + Send + 'static,
    Message: Send + 'static,
    HandleMessageFuture: Future<Output = Result<Option<Ctx>, HandleMessageErrorT>> + Send + 'static,
    HandleMessageErrorT: Into<Error> + Send, 

Creates a listener with the default error handler on its own system thread. It is safe to work with non-sync and non-send data in this listener. The callback (handle_message) will be invoked whenever a new item from the source stream is emitted. The context_factory is a closure you must provide that returns the initial state for the listener.