Justin Fagnani

This would be useful for polyfilling custom elements, but obviously that's not a good use case for why custom elements aren't enough. If I can page in my requests around...

@emilio @calebdwilliams and @vikerman I think standardized templating, along the lines of [Template Instantiation](https://w3c.github.io/webcomponents/proposals/Template-Instantiation.html) is a very valuable feature to explore, but it's a bit different than declarative shadow roots....

@davatron5000 what do you mean by "slot hoisting"? Instantiating declarative custom elements is definitely good future work, but it requires a lot more than what you've sketched to be practically...

I think it's important to be able to preserve the semantics of adopted stylesheets after round-tripping through shadow DOM serialization. Constructible StyleSheets are a shared CSSStyleSheet and that's observable as...

I would love to see TreeWalker be iterable as well.

To add a different use case, for which I don't think suppress would work, in the Custom Elements v1 polyfill, I want to be able to observe the main document...

From the Web Components world, I wouldn't be surprised if there are a few use cases that come up from needing to observe multiple shadow roots or ancestor trees as...

Edit: I didn't see that in this version of the idea the fragment doesn't live in the tree. I think that makes it functionally equivalent to NodePart from TemplateInstantiation, or...

Actually, it's not really a problem that `__forwardedRef` is minified. It's a property name entirely internal to the component. The only problem is that filtering it by string literal isn't...

The problem with fixing the `window` reference is that you'll then hit other references in lit-element, like `HTMLElement`. What we're doing in lit-ssr is creating a minimal DOM shim to...