Should throw on for (async of []);

[fisker]

Babel PR babel/babel#13208
Prettier issue prettier/prettier#10777

[KFlash]

@3cp It will be very challenging to fix this without a lookahead ...

[3cp]

Then forgot about it 😂

[3cp]

undefined is not a keyword which is one of the initial design mistakes of JS.
async is not a keyword because it's an added feature which cannot be made as a keyword without breaking legacy JS code.
JS parser is really not a pleasant artefact to work with. 😂

[KFlash]

I think you can throw an error if you pass down an context mask or something. In the future I will figure out how to solve it without a lookahead, but for now this is how I solved it in Kataw.

[KFlash]

@3cp It's possible to solve this without a lookahead. Just return the 'async' identifier if you see the 'of' keyword and deal with the rest of the logic in 'parseForStatement'. Very easy to solve 👍