jack-guy

class AppComponent {
  constructor () {
    this.count = 5;
    this.onResize = this._onResize.bind(this);
  }

  componentDidMount () {
    window.addEventListener('resize', this.onResize)
  }

jack-guy

export class AppComponent {
  onDestroy$ = new Subject();
  count = 5;

  ngOnInit () {
    this.iceCreams$ = fromEvent(window, 'resize').pipe(
      flatMap(() => fromPromise(fetchIceCreams(this.count))),
      takeUntil(this.onDestroy$)
    );
  }

jack-guy

const filterLoggedIn$ = (stream$) => {
  return stream$.pipe(
    withLatestFrom(iceCreamAuth$),
    filter((auth) => auth)
  )
};

const combinedInfoFactory$ = (
  iceCreamPreferences$,
  iceCreamInventory$,

jack-guy

from(iceCreamIds).pipe(
  withLatestFrom(
    iceCreamAuth$,
    iceCreamPreferences$,
    iceCreamVendors$,
    iceCreamInventory$,
    iceCreamTemperature$,
  ),
  map(([

jack-guy

import { from, fromPromise } from 'rxjs';
const iceCreamIds = [4, 5, 10, 12];
from(iceCreamIds).pipe(
  flatMap((iceCreamId) => fromPromise(getIceCreamById(iceCreamId)))
).subscribe((iceCream) => {
  console.log(iceCream);
});

jack-guy

function getIceCreamById (iceCreamId) {
  return fetch(`/icecream/${id}`);
}
const iceCreamIds = [4, 5, 10, 12];

// Slow, effectively synchronous
for (let iceCreamId of iceCreamIds) {
  console.log(await getIceCreamById(iceCreamId));
}

jack-guy

import { from, fromEvent, zip } from 'rxjs';
import { scan } from 'rxjs/operators';

const initialIceCreamFlavors = ['vanilla', 'chocolate', 'strawberry'];
const initialIceCreamPrices = ['$5.50', '$5.75', '$6.00'];

const iceCreamFormSubmit$ = fromEvent(formEl, 'submit');
const iceCreamFormFlavors$ = iceCreamFormSubmit$.pipe((map(({flavor}) => flavor)));
const iceCreamFormPrices$ = iceCreamFormSubmit$.pipe((map(({price}) => price)));

jack-guy

function getIceCreamFlavorToPrice(flavors, prices) {
  let iceCreamFlavorToPrice;
  for (let i = 0; i < flavors.length; i++) {
    iceCreamFlavorToPrice[flavors[i]] = prices[i];
  }
  return iceCreamFlavorToPrice;
}

let iceCreamFlavors = ['vanilla', 'chocolate', 'strawberry'];
let iceCreamPrices = ['$5.50', '$5.75', '$6.00'];

jack-guy

import { from, zip } from 'rxjs';
import { scan } from 'rxjs/operators';

const iceCreamFlavors = ['vanilla', 'chocolate', 'strawberry'];
const iceCreamPrices = ['$5.50', '$5.75', '$6.00'];

const iceCreamFlavorToPrice$ = zip(
  from(iceCreamFlavors),
  from(iceCreamPrices),
).pipe(scan((prev, [flavor, price]) => {

jack-guy

const iceCreamFlavors = ['vanilla', 'chocolate', 'strawberry'];
const iceCreamPrices = ['$5.50', '$5.75', '$6.00'];

let iceCreamFlavorToPrice;
for (let i = 0; i < iceCreamFlavors.length; i++) {
  iceCreamFlavorToPrice[iceCreamFlavors[i]] = iceCreamPrices[i];
}