Example for rx.Observable chaining

rx.Observable.chaining.example.groovy

@Grab(group='io.reactivex', module='rxjava-reactive-streams', version='0.5.0')
import rx.Observable

def in1 = Observable.from([1, 3, 5]).map { a -> a - 1 }
def in2 = Observable.from([2, 4, 6]).map { a -> a - 1 }
def in3 = Observable.error(new Exception("BAM!"))

def sumTimes2 = Observable.zip(in1, in2) { a, b ->
    a + b
}.map { a ->
    2 * a
}
def multTimes2 = Observable.zip(in1, in2, in3) { a, b, c ->
    a * b * c
}.map { a ->
    2 * a 
}

def emptyZip = Observable.zip([]) { -> println("this is never executed") }


sumTimes2.subscribe(
    { result -> println("sum: " + result) },
    { t -> println("sumE: " + t) }
)

multTimes2.subscribe(
    { result -> println("mult: " + result) },
    { t -> println("multE: " + t) }
)

/*
 * output
 *
 * sum: 2
 * sum: 10
 * sum: 18
 * multE: java.lang.Exception: BAM!
 */