Can someone explain why `Result` was added to the standard lib, when it’s effectively useless outsid...

# coroutines

[zak.taccardi]

Can someone explain why Result was added to the standard lib, when it’s effectively useless outside of Coroutines?

https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-result/

A standard Result<T> type that we could use as a return value would be incredible useful, and this seems to be a waste of a namespace?

[zak.taccardi]

I guess in the future it could be useful? https://github.com/Kotlin/KEEP/blob/master/proposals/stdlib/result.md#future-advancements

[Zach Klippenstein (he/him) [MOD]]

Why is it useless outside of coroutines?

[zak.taccardi]

I just really want to use it as a return type

[zak.taccardi]

maybe that just means I don’t fully understand it

[Zach Klippenstein (he/him) [MOD]]

Oh, because of the error? The release notes for 1.3.70 said they lifted restrictions on it, I just assumed that’s what they meant. But yea it doesn’t look like they did.

[Zach Klippenstein (he/him) [MOD]]

Well, I could have sworn I saw that in the release notes somewhere… but now I can’t find it.

[Zach Klippenstein (he/him) [MOD]]

Ah, damn, it’s coming in 1.4: https://github.com/JetBrains/kotlin/commit/1889376abaf89a5206b19587a3bbccd2133022e1#diff-e705c8fadf1193ab59443a5e6c8cbe8b

[zak.taccardi]

oh wow this is a big deal. We’re an internal company SDK so I don’t think we should be using experimental APIs like inline class yet though

[zak.taccardi]

(btw, I ❤️ the experimental stuff Kotlin does. Allows for great feedback and iteration. I couldn’t imagine coroutines without CoroutineScope)

[Zach Klippenstein (he/him) [MOD]]

And who knows when inline classes are going to stabilize. I don’t think I’ve seen anything about that for 1.4 😞

[zak.taccardi]

inline classes can’t be consumed from Java right though? So using Result<T> on a public API that may be called from Java would be a problem?

[Zach Klippenstein (he/him) [MOD]]

I think they can, but it boxes them so you don’t get the optimizations. I’m a bit rusty on the details there though.