Observable scheduler examles

example.ts

import * as Rx from 'rxjs/Rx';

function getVal(arr1, arr2){
    const obs = Rx.Observable.combineLatest(
        Rx.Observable.from(arr1), Rx.Observable.from(arr2)
    )
    //.let(filterFunc) // defined elsewhere assume somewhat complicated logic
    .reduce( (accum, val) => [...accum, val], [] )
    .catch( err => Rx.Observable.of(`an error while filtering ${err.data}`))

    let combined;
    obs.subscribe( 
        arr => combined = arr, 
        error => {
            console.error(error);
            combined = [];
        }
    )
    return combined;
}

function getAsyncVal(arr1, arr2){
    const wrap = arr => new Promise( resolve => resolve(arr));


    const obs = Rx.Observable.combineLatest(
        Rx.Observable.fromPromise(wrap(arr1)),
        Rx.Observable.fromPromise(wrap(arr2))
    )
    .reduce( (accum, val) => [...accum, val], [] )
    .catch( err => Rx.Observable.of(`an error while filtering ${err.data}`))


    let combined;
    obs.subscribe( 
        arr => combined = arr, 
        error => {
            console.error(error);
            combined = [];
        }
    )
    return combined;
}

console.log(getVal([1,2,3], [3,2,1]));

console.log(getAsyncVal([1,2,3], [3,2,1]));

/* output */
// [ [ 3, 3 ], [ 3, 2 ], [ 3, 1 ] ]
// undefined