bearing in mind all those functions are persistent (ie local factories), can you not write a simple

asIterable()

extension function on your external class?

Won’t that create a new object? What’s nice about the extension functions is that they don't

an

iterable

object gets allocated every time you write a for-each loop, and even with the most abusive kotlin code you can write I still suspect you wont hit the JVM as hard as a run-of-the-mill scala program. I think your committing an act of premature-optimization if your worried about an

asIterable

extension method that allocates the few dozen bytes needed for an Iterable instance thrashing the GC.