List of transformations:  https://GitHub.com/ReactiveX/rxjs/tree/master/src/operator

Examples:

• debouce Time  (Waits until a time before firing)
• throttleTime (emits a value then waits a time before emitting any further)
• distinctUntilChanged (Only reacts once and ignores duplicate items)

We use this by adding like so:

import 'rxjs/add/operator/debounceTime'

myControl.valueChanges.debounceTime(2000).subscribe(v => this.message(message));