RxJava delay for each item of list emitted

Question

I\'m struggling to implement something I assumed would be fairly simple in Rx.

I have a list of items, and I want to have each item emitted with a delay.

It

Answer 1

For kotlin users, I wrote an extension function for the 'zip with interval' approach

import io.reactivex.Observable
import io.reactivex.functions.BiFunction
import java.util.concurrent.TimeUnit

fun  Observable.delayEach(interval: Long, timeUnit: TimeUnit): Observable =
    Observable.zip(
        this, 
        Observable.interval(interval, timeUnit), 
        BiFunction { item, _ -> item }
    )

It works the same way, but this makes it reusable. Example:

Observable.range(1, 5)
    .delayEach(1, TimeUnit.SECONDS)