# \[Bikeshedding\]: Supporting throwing transforms on Result

**URL:** <https://forums.swift.org/t/bikeshedding-supporting-throwing-transforms-on-result/21698>\
**Category:** Discussion\
**Created:** [March 17, 2019, 4:19am UTC](https://forums.swift.org/t/bikeshedding-supporting-throwing-transforms-on-result/21698 "2019-03-17T04:19:37Z")\
**Posts on this page:** 1\
**Showing post:** 12

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**Author:** ![gwendal.roue](https://sea2.discourse-cdn.com/swift/user_avatar/forums.swift.org/gwendal.roue/32/13992_2.png) [@gwendal.roue](https://forums.swift.org/u/gwendal.roue)\
**Post date:** [March 18, 2019, 7:09pm UTC](https://forums.swift.org/t/bikeshedding-supporting-throwing-transforms-on-result/21698/12 "2019-03-18T19:09:04Z")

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I don't understand. Nobody has any problem with applying multiple throwing transformations. The problem lies in the frontier between Result-based apis, and regular throwing methods (which **are** the idiomatic way to transform values with eventual error). It is very simple, and has been well explained: there is no point stating it again.

A flatMap with a throwing closure has been requested during the pitch, the review, and regrets have been expressed after SE-0235 had shipped without it. The rationale did not close the door:

> [@\[Accepted with Modifications\] SE-0235: Add Result to the Standard Library](https://forums.swift.org/t/accepted-with-modifications-se-0235-add-result-to-the-standard-library/18603/1):
>
> Several members of the community voiced disappointment that the proposal did not include a variant of `flatMap` that took a throwing closure. The Core Team reaffirms its desire to never overload methods by whether an argument function can throw. We spent quite some time debating whether a different name would be acceptable, such as `flatMapThrowing` , but were unable to reach consensus on this, especially as there are alternative means of expressing this using the catching initializer.

Edit: it's just a discussion about a convenience API, nothing more... There is no "big problem in Swift"...

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