<script>
import { BehaviorSubject, operators } from "rxjs@6.5.1/bundles/rxjs.umd.min.js"
const { map } = operators
const o$ = new BehaviorSubject("John")
o$.set = o$.next
const reverse$ = o$.pipe(
map(text => text.split("").reverse().join(""))
)
</script>
<input bind:value={$o$}/>
<p>
{$o$}
</p>
<p>
{$reverse$}
</p>