Selector provide by useAtomValue

[yf-yang]

I checked #2001

Although it is rejected, I still want to discuss a scenario:

function useAtomWithFunctionScopeValue(v) {
  const arr = useAtomValue(myArrayAtom);
  return arr[v];
}

Suppose I need such a hook, from its implementation we know it is better rerendered when arr[v] changes, instead of rerender every time the array changes. Since v is provided when using the hook, is there any solution to achieve such an ability?

Inspired by https://ariakit.org/guide/component-stores#computed-values

[dai-shi]

function useAtomWithFunctionScopeValue(v) {
  const  vAtom = useMemo(() => atom((get) => get(myArrayAtom)[v]), [v]);
  return useAtomValue(vAtom);
}

[yf-yang]

function useAtomValueWithSelector(a, selector, deps) {
  const r = useMemo(() => atom(get => get(a)), [a]);
  const s = useMemo(() => selectAtom(r, selector), [r, deps]);
  return useAtomValue(s);
}

[dai-shi]

BTW, why selectAtom must be called with read only atom?

Are you sure about it?

[yf-yang]

It's from the doc. Actually I don't think so
https://jotai.org/docs/recipes/large-objects#selectatom

[dai-shi]

It's a doc issue, I guess. It should take a read-write atom, but returns only a read-only atom. Would you please send a PR to fix the doc?

[yf-yang]

Sure, later today