Class EventEmitter<EventMap>

Delivers event to the listeners registered for type in registration order. Re-entrant emission of type is deferred (rule 4).

Number of live registrations for type (diagnostics, §83).

Number of live listener registrations across every event type (§83).

Used by teardown diagnostics — a detached node that still holds listeners pins its subtree until those listeners are removed.

Removes the earliest still-registered registration of listener for type. Removing a listener that is not registered is a no-op.

Registers listener for type. Returns a function that removes it.

The same listener may be registered more than once; each registration is independent and is delivered once per dispatch.

Registers listener for a single delivery. Returns an unsubscriber.

Removes every listener, or every listener of one type. Used by teardown paths that must not leave detached nodes retaining listeners (§83).