There is a small library called RxKotlin (https://github.com/ReactiveX/RxKotlin/), which we made a dependency at the beginning of this chapter. At the time of writing this, it is hardly a complex library but rather a small collection of convenient extension functions for common reactive conversions. It also attempts to standardize some conventions when using RxJava with Kotlin.
For instance, there are the toObservable() and toFlowable() extension functions that can be invoked on iterables, sequences, and a few other sources. In the following code, instead of using Observable.fromIterable() to turn a List into an Observable, we just call its toObservable() extension function:
import io.reactivex.rxkotlin.toObservable
fun main(args: Array<String>) {
val myList = listOf("Alpha", "Beta", "Gamma", "Delta",
"Epsilon")
myList.toObservable()
.map(String::length)
.subscribe(::println)
}There are some other extensions in RxKotlin worth...