# Publishers.TryComparison A publisher that republishes items from another publisher only if each new item is in increasing order from the previously-published item, and fails if the ordering logic throws an error. ``` struct TryComparison where Upstream : Publisher ``` ## Topics ### Creating a try-comparison publisher [`init(upstream: Upstream, areInIncreasingOrder: (Upstream.Output, Upstream.Output) throws -> Bool)`](/documentation/Combine/Publishers/TryComparison/init(upstream:areInIncreasingOrder:)) Creates a publisher that republishes items from another publisher only if each new item is in increasing order from the previously-published item, and fails if the ordering logic throws an error. ### Declaring supporting types [`typealias Output`](/documentation/Combine/Publishers/TryComparison/Output) The kind of values published by this publisher. [`typealias Failure`](/documentation/Combine/Publishers/TryComparison/Failure) The kind of errors this publisher might publish. ### Inspecting publisher properties [`let upstream: Upstream`](/documentation/Combine/Publishers/TryComparison/upstream) The publisher from which this publisher receives its elements. [`let areInIncreasingOrder: (Upstream.Output, Upstream.Output) throws -> Bool`](/documentation/Combine/Publishers/TryComparison/areInIncreasingOrder) A closure that receives two elements and returns true if they are in increasing order. ## Relationships ### Conforms To [`Publisher`](/documentation/Combine/Publisher) --- 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)