It's loosely based on Proust ASAP, but without the explicit quadratic-time construction of paths (in a sense, this is done 'dynamically' at runtime with the CoW strategy we've discussed). When you think about it, Vaporization is really just an extension to escape analysis. It's not a perfect system though, namely, It required immutable closures. But if you're coming from a functional programming language, that's a small sacrifice to make, given that mutability is generally frowned upon.

> I think I'll have at least one more question about how the "tying of references to the stack" works, but I need to think things through a bit more.

I tried to answer your sibling comment on appending a CoW xs. I hope that clears some things up so you can ask any questions you have!