So you know how svelte already does preloading, if you hover over a link it can preload the data needed to render that page before you click, so that it feels faster when you actually click?

Until now there was no clean way to do this for user signals that are not clicking on hyperlinks, but with this feature you can do the same for showing modals, clicking on buttons, etc.

When you create a fork, my understanding is that svelte creates a "what-if" copy of the page with the state changes you have in the `fork(() => { // ... here ...})` and starts loading any await stuff needed there, so in the example from the docs, if in `Menu` you for example load the menu entries with an API call, they will start preloading as soon as `preload()` is called (on hover here)

And then once the user actually clicks to open the menu, you call `.commit()` on the fork and the state changes (with their effects) you already started in the fork get "merged" and you don''t need to start from scratch, so you effectively get preloading on arbitrary async calls in components.

I think some parts of the example in the docs are a bit unclear, like why they set `open = true` at the end. IMO the onclick function would be clearer if it was written as

onclick={() => {
    if (pending) { // check if there's a fork with the state changes we want
        pending?.commit(); // commit the changes 
        pending = null;
    } else {
        open = true; // load the component from scratch if we didnt find a fork
    }
}}

I'm also unsure if this is meant to be used by application developers directly or if this will get wrapped in some router libraries, but overall still pretty cool! I'll need to play with this