Any easy way to make a class implementing `operato...

# announcements

[dave08]

Any easy way to make a class implementing operator iterator() that returns a custom iterator that implements operator hasNext() and operator next(), to return a List? It seems that currently the only way is to make a mutable list and then for (e in iterator) list.add(e)...?

[fourlastor]

I think you want to use List constructor

[fourlastor]

val list = List(count, { index -> valueFor(index) })

[fourlastor]

or maybe there's a way to instantiate the list via the iterator

[fourlastor]

https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/to-list.html this maybe?

[dave08]

I'm asking because of the ReceiveChannel in coroutines, but it doesn't implement Iterable, it just defines operators for in to work...

[dave08]

@fourlastor The List constructor won't help, since I don't have indexed retrieval only hasNext and next operators...

[fourlastor]

you can create an iterable with Iterable, let me look up the function

[fourlastor]

and then use toList()

[fourlastor]

https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-iterable.html this 🙂

[dave08]

The definition of the function is:

public inline fun <T> Iterable(crossinline iterator: () -> Iterator<T>): Iterable<T> = object : Iterable<T> {
    override fun iterator(): Iterator<T> = iterator()
}

Doesn't help in this case... since my iterator() function doesn't return a real Iterable, oh well I guess back to the harder way... 😢