Why Kotlin does not have `Either` class? <https://...

# stdlib

[rrader]

Why Kotlin does not have Either class? https://www.scala-lang.org/api/2.9.3/scala/Either.html

[Mike]

It's not trying to be fully functional. Doesn't have option, try and others either. If you want that, the 'standard' is arrow-kt. #arrow

[rrader]

Well, it has Option as nullable types

[rrader]

We need Either to implement supporting for undefined like in JavaScript

[rrader]

Something like Either<Int, Nothing> or Either<String?, Nothing>

[rrader]

And undefined we need for https://medium.com/workflowgen/graphql-mutations-partial-updates-implementation-bff586bda989

[aarjav]

I believe Kotlin way might be to use sealed classes. One benefit is you can even add 3rd case hopefully without too much code change.

[robin]

Just for completeness' sake, nullable types in Kotlin are not really equivalent to a dedicated Option class, most notably because they can't be nested without losing information