/** PURE_IMPORTS_START .._operators_switchAll PURE_IMPORTS_END */ import { switchAll as higherOrder } from '../operators/switchAll'; /** * Converts a higher-order Observable into a first-order Observable by * subscribing to only the most recently emitted of those inner Observables. * * Flattens an Observable-of-Observables by dropping the * previous inner Observable once a new one appears. * * * * `switch` subscribes to an Observable that emits Observables, also known as a * higher-order Observable. Each time it observes one of these emitted inner * Observables, the output Observable subscribes to the inner Observable and * begins emitting the items emitted by that. So far, it behaves * like {@link mergeAll}. However, when a new inner Observable is emitted, * `switch` unsubscribes from the earlier-emitted inner Observable and * subscribes to the new inner Observable and begins emitting items from it. It * continues to behave like this for subsequent inner Observables. * * @example