Struct EventBus 

pub struct EventBus { /* private fields */ }

The serial event dispatcher.

Implementations

impl EventBus

pub fn new(rx: Receiver<Event>) -> Self

Build a new bus from an mpsc receiver. The paired Sender must be held by callers (and shared to sources) so they can push events.

pub fn on( &mut self, kind: impl Into<String>, handler: HandlerKey, ) -> Result<(), BlockError>

Register a kind-specific handler. Last write wins — re-registering the same kind silently replaces the previous handler (documented in plan.md §Phase 3 / wf-sim Counter-WF).

Returns Err(BlockError::Bus) if called after EventBus::run has begun.

pub fn on_any(&mut self, handler: HandlerKey) -> Result<(), BlockError>

Register the on_any fallback. Invoked only when no on(kind) handler matches the event’s kind. NOT a fan-out/tap.

pub async fn run( &mut self, shutdown: CancellationToken, ) -> Result<(), BlockError>

Drive the dispatcher loop until shutdown is cancelled.

Cancel-safety: mpsc::Receiver::recv is cancel-safe; dropping the select! branch on the recv side loses no events (tokio docs). CancellationToken::cancelled is explicitly designed for this usage (tokio-util docs).