ViewHolder

RecyclerView

ViewHolder

ERR: stack=java.lang.NullPointerException: subscribeActual failed

@Throws(Throwable::class)
    override fun onRun() {
              //synchronous stream....
                .subscribe(
                        {},
                        { throw it } //I need this exception to be thrown to the wrapping `onRun` method
                )
    }

@Test fun shouldBlowYourMind() {
    Observable.empty<Unit>().test().assertEmpty()
}

java.lang.AssertionError: Completed! (latch = 0, values = 0, errors = 0, completions = 1)

networkLoad()
    .subscribeOn(io())
    .startWith(cacheCompute())
    .subscribeOn(computation())
    .observeOn(mainThread())

fun <T1, T2, T3, R> asyncCombineLatest(o1: Observable<T1>,
                                                   o2: Observable<T2>,
                                                   o3: Observable<T3>,
                                                   asyncCombineFunc: (T1, T2, T3) -> Observable<R>): Observable<R> =
            Observable.combineLatest(o1, o2, o3) { a, b, c -> Triple(a, b, c) }
                    .flatMap { bundle ->
                        val (a, b, c) = bundle
                        asyncCombineFunc(a, b, c)
                    }

groupby

val intentions = ui.intentions()
                .map {
                    fun handleUiInput(intention: Intention): Unit = when (intention) {
                        is Intention.BooleanPreferenceWithChange -> {
                            intention.preference.db.set(newValue = intention.change)
                        }
                        is Intention.NumberPreferenceWithChange -> {
                            taxDb.write(intention.change)
                        }
                    }
                    handleUiInput(it)
                }

when

sealed class

kotlinx-coroutines-reactive