onError property
Optional recovery for a failure thrown while computing a single event.
When non-null, a thrown error is mapped to a fallback TOutput (one
fallback per failing event — failures are never collapsed or deduplicated)
instead of erroring the stream. When null, the error is rethrown onto the
output stream. If this callback itself throws, that error surfaces on the
stream rather than being swallowed.
Audited: 2026-06-12 11:26 EDT
Implementation
final TOutput Function(Object error, StackTrace stackTrace)? onError;