Is there any easy way in KSP to get the closest co...

# ksp

[Jake Woods]

Is there any easy way in KSP to get the closest common ancestor of two KSType? I’m doing the resolution with a hand-written algorithm right now and it feels wrong

[Jake Woods]

For example, say I have a KSType of Either<Nothing, Int> and another of Either<Throwable, Nothing>, I want to infer that their common ancestor is Either<Throwable, Int>

[Jiaxiang]

It doesn’t really work as a common ancestor, you need to have variance in order to make it a common ancestor, for example you need to have Either<out T, out P> declared. Even after that, you still need to manually write a least common ancestor algorithm to determine the common ancestor you are looking for, and you also need to deal it with recursively as the type arguments can still be generics.

[Jake Woods]

In this example Either is defined as Either<out E, out T> so I think the ancestor exists. I guess I was hoping KSP already had a least common ancestor implementation but it sounds like I'll need to roll my own 🙂

[Jiaxiang]

ah yes, you need to implement it yourself. This is not a common enough use case to be included in public API.