"use strict"; var isScheduler_1 = require('../util/isScheduler'); var of_1 = require('./of'); var from_1 = require('./from'); var concatAll_1 = require('../operators/concatAll'); /* tslint:enable:max-line-length */ /** * Creates an output Observable which sequentially emits all values from given * Observable and then moves on to the next. * * Concatenates multiple Observables together by * sequentially emitting their values, one Observable after the other. * * * * `concat` joins multiple Observables together, by subscribing to them one at a time and * merging their results into the output Observable. You can pass either an array of * Observables, or put them directly as arguments. Passing an empty array will result * in Observable that completes immediately. * * `concat` will subscribe to first input Observable and emit all its values, without * changing or affecting them in any way. When that Observable completes, it will * subscribe to then next Observable passed and, again, emit its values. This will be * repeated, until the operator runs out of Observables. When last input Observable completes, * `concat` will complete as well. At any given moment only one Observable passed to operator * emits values. If you would like to emit values from passed Observables concurrently, check out * {@link merge} instead, especially with optional `concurrent` parameter. As a matter of fact, * `concat` is an equivalent of `merge` operator with `concurrent` parameter set to `1`. * * Note that if some input Observable never completes, `concat` will also never complete * and Observables following the one that did not complete will never be subscribed. On the other * hand, if some Observable simply completes immediately after it is subscribed, it will be * invisible for `concat`, which will just move on to the next Observable. * * If any Observable in chain errors, instead of passing control to the next Observable, * `concat` will error immediately as well. Observables that would be subscribed after * the one that emitted error, never will. * * If you pass to `concat` the same Observable many times, its stream of values * will be "replayed" on every subscription, which means you can repeat given Observable * as many times as you like. If passing the same Observable to `concat` 1000 times becomes tedious, * you can always use {@link repeat}. * * @example