When targeting Java interop, what type should one use for a lazy collection? Sequence<T> makes the most sense for Kotlin callers due to extension functions on it being lazy by default, but forces Java callers to deal with a Kotlin stdlib type and convert the sequence iterator manually (sequence does not extend iterable!) Iterable<T> makes sense for Java callers due to implicit usage in for loops, but will cause unsuspecting Kotlin callers to accidentally drop laziness due to non-lazy extension functions Stream<T> is optimal for both Java and Kotlin callers but may have overhead and is Java 8+ (Kotlin targets 6+)

Kotlin, targeting Java interop: Idiomatic type for lazy collection?

When targeting Java interop, what type should one use for a lazy collection?

Sequence<T> makes the most sense for Kotlin callers due to extension functions on it being lazy by default, but forces Java callers to deal with a Kotlin stdlib type and convert the sequence iterator manually (sequence does not extend iterable!)
Iterable<T> makes sense for Java callers due to implicit usage in for loops, but will cause unsuspecting Kotlin callers to accidentally drop laziness due to non-lazy extension functions
Stream<T> is optimal for both Java and Kotlin callers but may have overhead and is Java 8+ (Kotlin targets 6+)