"await" within array comprehension returns a parse error

[nolanlawson]

This async function tries to return an array of values concurrently resolved by different Promises (i.e. an equivalent for Promise.all()):

async function demo() {
  try {
    let things = ['foo', 'bar', 'baz'];

    let promises = things.map((thing) => returnAPromise(thing));

    let results = [for (promise of promises) await promise];

    console.log('posted many docs simultaneously, results are ', results);
  } catch (err) {
    console.log(err);
  }
}

This fails with an error:

Error : Parsing file /.../index.js: Unexpected token (40:38)

My current workaround is to build up the results array like this:

let results = [];
for (let promise of promises) {
  results.push(await promise);
}

I have a live example of the code here. To reproduce, just check out the code and do npm i && npm run build.

Thanks in advance, and let me know if this is just an error in my understanding or not in Regenerator.