[flanbiscuit]

I wonder how much of that came from this TS to JSDoc change Rich Harris talked about here: https://news.ycombinator.com/item?id=35892250

> I _would_ say that this will result in no changes that are observable to users of the framework, but that's not quite true — it will result in smaller packages (no need to ship giant sourcemaps etc), and you'll be able to e.g. debug the framework by cmd-clicking on functions you import from `svelte` and its subpackages (instead of taking you to an unhelpful type declaration, it will take you to the actual source, which you'll be able to edit right inside `node_modules` to see changes happen).

[benmccann]

A lot! Sourcemaps are often twice the size of the code itself.