fr: Add a way to scope atoms

[jvliwanag]

Looking for a way to scope atom instances within a subtree, similar to jotai-scope [gh].

Note we're talking about scope as in jotai's usage, not Effect.

[user-0a]

+1, just ran into wanting something like this today.

For context, our situation is that we have some data coming from an external library's hook that we want to wire up into Effect Atom. We were thinking we could just provide in a RegistryProvider but that doesn't work as it assumes the provided values never change. We want to do something like this:

function Page() {
  const userSetting = useExternalData();
  
  return <ScopedProvider values={[userSettingAtom, userSetting]}> <PageInner /> </ScopedProvider>
}

At the moment we're working around this with a hacky solution with useEffect + setUserSetting, etc. but ScopedProvider would allow us to solve this cleanly.

[tim-smart]

I don't think a scoped registry is the best solution here as it introduces footguns when using atoms with effect services.

I think a react specific solution will be needed as you are tying state to the component tree.

Will take a look when I get some time.

[user-0a]

I just wanted to follow up on this, is there a recommended way to handle the situation of tying state to the component tree?