Камрады, вопрос по самым азам Свелта. ( да и по

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Svelte [svelt] - All about Svelte JavaScript framework.

Камрады, вопрос по самым азам Свелта. ( да и по

Реакту заодно )
Как правильно соотнести аналоги различных инициализаций?

let varName == const [varName, fn] = useState() == constructor(){ this.state = {varName}} == data(){return {varName} } == ref({varName})
export let varName == ({varName}) == constructor(){ super(props) } == props: [ 'varName' ] == props: [ 'varName' ]
function == function == function == watch / computed / methods == watch / computed / methods
export function == ??? == function == watch / computed / methods == watch / computed / methods

$: == useEffect() / useMemo == ??? == watch / computed == watch / computed
<script> ... </script> == ??? == ??? == ??? == ???
<html /> == render == render == template / render == template / render

onMount == useEffect( ??? ) == componentDidMount == created / mounted == created / mounted
beforeUpdate == useEffect( ??? ) == ??? == beforeUpdate == beforeUpdate
afterUpdate == useEffect( ??? ) == componentDidUpdate == updated == updated
onDestroy == useEffect( ??? ) == componentWillUnmount == unmounted??? == unmounted???