How to run Generator Functions in Parallel?

Assuming I have a Koa web server with an endpoint like this:

const perform = require(...); // some generator function

exports.endpoint = function* () {

    var results = yield getResults();

    // Respond the results
    this.body = results;
}

exports.getResults = function* () {

    var actions = [...];
    var results = [];

    for (var action of actions) {

        var result = yield perform(action);

        results.push(results);
    }

    return results;
}

Now the client will get the respond after ALL the actions are performed obviously. but the things is each action is dependent on the completion of the previous.

Is there a way to execute them in parallel?

Note: Turning them to Promises is not an option, unless I can somehow return the results, and not resolve() them.

via Shai Ben-Dor