# callAsFunction(to:eventHandler:) Performs the transformation on a sequence of inputs. ``` func callAsFunction(to input: S, eventHandler: EventHandler? = nil) async throws -> [Self.OutputSequence] where S : Sequence, Self.Input == S.Element.Feature, S.Element : TemporalSequence ``` ## Parameters `input` The transformer inputs. `eventHandler` An event handler. ## Return Value The outputs produced by applying the transformer to the inputs. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)