If I have some

data class ApplicationError(val cause: ApplicationError?)

, is there a neat way to flattern this which my potentially be something like

val cause = error.cause.cause.cause.cause.cause.cause.cause.cause

illustrating how long the chain may be

This will cause an infinite loop in case of a cycle, but:

tailrec fun ApplicationError.rootCause(): ApplicationError? = cause?.rootCause()

I don't think there can be a loop since the nested ApplicationError has to be passed during construction, so it has to already be initialized before this one, which means it can't have a nested ApplicationError that we're currently constructing. If the

val

was a

var

then yes, there could potentially be a loop.

I was thinking of having a function recursively call itself until a null cause is hit, seeding into an arraylist, but it feels wrong

@Davio Oh yes I see what you mean. Agreed, I don't think there's any way to get a cycle out of it. @Kev that's what my solution kind of does, but it uses tailrec so no real recursion, and instead of seeding into an array list, theoretically you could make a sequence out of it and convert that to a list, but my solution is just easier I think