Didn't see support for this in the documentation, but it would be great if Flow supported type annotations in comments (or similar) – with the aim of allowing everything to be written in pure JavaScript.

This would allow people to keep the same tools they currently use, and skip the transpilation step.

Has this idea been floated at all? Is it doable?

Edit:
Looks like this is doable – perhaps the documentation just needs to be updated to expound on this?
Edit again:
OK, so atm it's just conversion from docblock to flow – would be great if it could be done in-place... or something