Hey everyone :wave: I am trying to write a "circul...

# announcements

[tyrondis]

Hey everyone 👋 I am trying to write a "circular" iterator that works like so:

val it = (1..3).circularIterator()
it.next() // 1
it.next() // 2
it.next() // 3
it.next() // 1
// and so on...

Any ideas how I can accomplish this? Is there already something similar in the stdlib?

[diesieben07]

fun <R> Iterable<R>.circularIterator(): Iterator<R> {
    return iterator { 
        while (true) {
            yieldAll(this@circularIterator)
        }
    }
}

Comes to mind

[diesieben07]

You might want to use a Sequence instead of an iterator though, in which case you can just replace iterator { } with sequence { }

[tyrondis]

Nice! Works like a charm, thank you!

[tyrondis]

Why would a Sequence be better here?

[diesieben07]

A Sequence would allow you to further perform operations on the data (such as filter, map, etc.) and also allow iterating it multiple times.

[tyrondis]

That makes sense, thanks for the clarification!