Transforms elements from the upstream publisher by providing the current element to an error-throwing closure along with the last value returned by the closure.
- iOS 13.0+Beta
- macOS 10.15+Beta
- Mac Catalyst 13.0+Beta
- tvOS 13.0+Beta
- watchOS 6.0+Beta
- Xcode 11.0+Beta
The previous result returned by the
An error-throwing closure that takes as its arguments the previous value returned by the closure and the next element emitted from the upstream publisher.
A publisher that transforms elements by applying a closure that receives its previous return value and the next element from the upstream publisher.
If the closure throws an error, the publisher fails with the error.