[wlib]

The biggest benefit to this is that it makes one of the slowest parts of virtual DOM diffing (longest common subsequence) no longer required. After this becomes supported in the mainstream, not even signal-based frameworks will have to include VDOM algorithms. I know this because I remember pushing for this to be supported a few years ago — a nice reminder that the standards are evolving and that nothing stops you from being a small part of the effort.

Next up — DOM parts and standardized signals, unified.

[spankalee]

DOM Parts + Signals will be an absolute game changer for the web platform.

Then there's a direct line to built-in declarative reactive templating: https://github.com/WICG/webcomponents/issues/1069

[giancarlostoro]

How do you even bring this up in a way that it gets noticed by the right people? There's so many times I read niche parts of the DOM that I feel need serious enhancements. I use Blazor (WASM) a lot more these days, so a lot of that is masked from me now.

[dimal]

Why would this eliminate the need for any VDOM algorithm? I could see how it would simplify VDOM diffing but not eliminate it altogether.

[spankalee]

VDOM hasn't been needed for a long while, if ever.

You can do a lot better just checking if the template that/s rendering to a spot in the DOM is the same or different from the previous template. If it's the same, just update the bindings from the template, if it's different re-render the whole thing.

That's simpler and faster, but the one thing it leaves out is stateful reordering of lists. So you can have a specific re-ordering code path, which is simpler than a full VDOM, but if you want to preserve state like moveBefore() does, even that reordering gets pretty complicated because you can only preserve state for one contiguous range of nodes that you don't actually move - instead you move all the other nodes around them. moveBefore() just eliminates all that extra complexity.

There's also a couple of standards issues open for native reordering of siblings, like reorderChildren(). That would eliminate the re-ordering code completely.

[notnullorvoid]

Signal based libraries already don't need VDOM. It's possible that it'll allow faster reordering of elements that are already connected, but the added checks needed to see if an element is connected (need to use insertBefore if not connected) might also cause overall perf regression. The main thing is that it allows elements to be moved without triggering disconnect/connect.