Exposing a variable as readonly

[ClementNerma]

Describe the problem

I have a variable that changes inside my component, like this:

<script lang="ts">
import { Focusable } from "..."
let focused = false
</script>

<Focusable onFocus={() => { focused = true }} onUnfocus={() => { focused = false }} />

I want to expose focused such as in other components I can do:

<script lang="ts">
let focused: boolean
</script>

<MyComponent bind:focused />

Describe the proposed solution

I don't know how this could be done - any idea?

Alternatives considered

Importance

would make my life easier

[Prinzhorn]

https://github.com/sveltejs/svelte/search?q=readonly+binding&type=issues
It this it? #7712

Or maybe you're new to Svelte and if you don't mind it being two way all your code is missing is an export.

<script lang="ts">
import { Focusable } from "..."
-let focused = false
+export let focused = false
</script>

<Focusable onFocus={() => { focused = true }} onUnfocus={() => { focused = false }} />

[ClementNerma]

Seems like it is. I'm not new to Svelte but I absolutely want a one-way binding, hence the read-only requirement.