function AsyncGenerator(gen) {
    var front, back;
    function send(key, arg) {
        return new Promise(function(resolve, reject) {
            var request = {
                key: key,
                arg: arg,
                resolve: resolve,
                reject: reject,
                next: null
            };
            if (back) {
                back = back.next = request;
            } else {
                front = back = request;
                resume(key, arg);
            }
        });
    }
    function resume(key, arg) {
        try {
            var result = gen[key](arg);
            var value = result.value;
            var wrappedAwait = value instanceof _AwaitValue;
            Promise.resolve(wrappedAwait ? value.wrapped : value).then(function(arg) {
                if (wrappedAwait) {
                    resume("next", arg);
                    return;
                }
                settle(result.done ? "return" : "normal", arg);
            }, function(err) {
                resume("throw", err);
            });
        } catch (err) {
            settle("throw", err);
        }
    }
    function settle(type, value) {
        switch(type){
            case "return":
                front.resolve({
                    value: value,
                    done: true
                });
                break;
            case "throw":
                front.reject(value);
                break;
            default:
                front.resolve({
                    value: value,
                    done: false
                });
                break;
        }
        front = front.next;
        if (front) {
            resume(front.key, front.arg);
        } else {
            back = null;
        }
    }
    this._invoke = send;
    if (typeof gen.return !== "function") {
        this.return = undefined;
    }
}
if (typeof Symbol === "function" && Symbol.asyncIterator) {
    AsyncGenerator.prototype[Symbol.asyncIterator] = function() {
        return this;
    };
}
AsyncGenerator.prototype.next = function(arg) {
    return this._invoke("next", arg);
};
AsyncGenerator.prototype.throw = function(arg) {
    return this._invoke("throw", arg);
};
AsyncGenerator.prototype.return = function(arg) {
    return this._invoke("return", arg);
};
function _asyncIterator(iterable) {
    var method;
    if (typeof Symbol === "function") {
        if (Symbol.asyncIterator) {
            method = iterable[Symbol.asyncIterator];
            if (method != null) return method.call(iterable);
        }
        if (Symbol.iterator) {
            method = iterable[Symbol.iterator];
            if (method != null) return method.call(iterable);
        }
    }
    throw new TypeError("Object is not async iterable");
}
function asyncGeneratorStep(gen, resolve, reject, _next, _throw, key, arg) {
    try {
        var info = gen[key](arg);
        var value = info.value;
    } catch (error) {
        reject(error);
        return;
    }
    if (info.done) {
        resolve(value);
    } else {
        Promise.resolve(value).then(_next, _throw);
    }
}
function _asyncToGenerator(fn) {
    return function() {
        var self = this, args = arguments;
        return new Promise(function(resolve, reject) {
            var gen = fn.apply(self, args);
            function _next(value) {
                asyncGeneratorStep(gen, resolve, reject, _next, _throw, "next", value);
            }
            function _throw(err) {
                asyncGeneratorStep(gen, resolve, reject, _next, _throw, "throw", err);
            }
            _next(undefined);
        });
    };
}
function _awaitAsyncGenerator(value) {
    return new _AwaitValue(value);
}
function _AwaitValue(value) {
    this.wrapped = value;
}
function _wrapAsyncGenerator(fn) {
    return function() {
        return new AsyncGenerator(fn.apply(this, arguments));
    };
}
function _generate() {
    _generate = _wrapAsyncGenerator(function*() {
        const results = yield _awaitAsyncGenerator(Promise.all([
            Promise.resolve(1),
            Promise.resolve(2),
            Promise.resolve(3), 
        ]));
        for (const result of results){
            console.log(`yield ${result}`);
            yield result;
        }
    });
    return _generate.apply(this, arguments);
}
function generate() {
    return _generate.apply(this, arguments);
}
function _printValues() {
    _printValues = _asyncToGenerator(function*() {
        const iterator = generate();
        {
            var _iteratorNormalCompletion = true, _didIteratorError = false, _iteratorError;
            try {
                for(var _iterator = _asyncIterator(iterator), _step, _value; _step = yield _iterator.next(), _iteratorNormalCompletion = _step.done, _value = yield _step.value, !_iteratorNormalCompletion; _iteratorNormalCompletion = true){
                    const value = _value;
                    console.log(`iterator value: ${value}`);
                }
            } catch (err) {
                _didIteratorError = true;
                _iteratorError = err;
            } finally{
                try {
                    if (!_iteratorNormalCompletion && _iterator.return != null) {
                        yield _iteratorError.return();
                    }
                } finally{
                    if (_didIteratorError) {
                        throw _iteratorError;
                    }
                }
            }
        }
    });
    return _printValues.apply(this, arguments);
}
function printValues() {
    return _printValues.apply(this, arguments);
}
printValues();