[onsclom]

Most of this I really love. One thing seems a bit strange though...

Let's compare Svelte's and Solid's approach to nested reactivity. Both of them implement the same nested reactivity todo example:

Svelte: https://svelte-5-preview.vercel.app/docs/fine-grained-reacti...

Solid: https://www.solidjs.com/tutorial/stores_nested_reactivity?so...

In Solid, converting something to use nested reactivity is one step. In Svelte, it is two steps. And that second step is really verbose and annoying:

  todos = [...todos, {
    get done() { return done },
    set done(value) { done = value },
    get text() { return text },
    set text(value) { text = value }
   }];

Solid makes read and write segregation very simple and obvious. You don't need to manually make all these getters and setters.

It is nice that runes allows nested reactivity in Svelte, but it feels nicer to use in Solid.

[rich_harris]

FWIW you can of course implement createSignal in four lines of code, if you prefer the ergonomics of that:

function createSignal(initial) { let value = $state(initial); return [() => value, (v) => value = $state(v)]; }

Note that the Solid change is _not_ 'one step' — the `completed` property is being turned from a property to a function, which means you must update all the usage sites as well. Using getters and setters also allows you to use Svelte's convenient `bind:value` approach, which is much less verbose than using the equivalent event handler code. And don't get me started on the [type narrowing issues](https://www.typescriptlang.org/play?#code/C4TwDgpgBA4hzAgJwD...).

There's nothing _wrong_ with the Solid approach, but the ergonomics aren't to our liking. If we need to take a hit in terms of verbosity, we'd rather do it once at the declaration site than n times at every usage site.

[onsclom]

These are great points! Thanks for the super thoughtful reply. I'm actually sold.

1. It's really nice that it's so easy to make a `createSignal`

2. I didn't realize that in Solid you had to update all the usage sites too, so now I'd rather stick to the Svelte usage. Nested reactivity is not as effortless as I thought in Solid.

  get done() { return done },
  set done(value) { done = value },
  get text() { return text },
  set text(value) { text = value }

Looks a bit boilerplate-y maybe, but keeping your preoptimized call sites is totally worth it.

This might be common enough that some syntax sugar might be worth it?

The short hand for:

  todos = [...todos, {
    get done() { return done },
    set done(value) { done = value },
    get text() { return text },
    set text(value) { text = value }
  }];

Could be:

  todos = [...todos, {
    $done,
    $set
  }];

[toastercat]

This is the biggest weirdness that I hope gets addressed.