"use strict";
Object.defineProperty(exports, "__esModule", {
    value: true
});
exports.default = AsyncGenerator;
var _awaitValue = _interopRequireDefault(require("./_await_value"));
function _instanceof(left, right) {
    if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) {
        return right[Symbol.hasInstance](left);
    } else {
        return left instanceof right;
    }
}
function _interopRequireDefault(obj) {
    return obj && obj.__esModule ? obj : {
        default: obj
    };
}
function AsyncGenerator(gen) {
    var send = 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);
            }
        });
    };
    var settle = 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;
        }
    };
    var front, back;
    function resume(key, arg) {
        try {
            var result = gen[key](arg);
            var value = result.value;
            var wrappedAwait = _instanceof(value, _awaitValue.default);
            Promise.resolve(wrappedAwait ? value.wrapped : value).then(function(arg1) {
                if (wrappedAwait) {
                    resume("next", arg1);
                    return;
                }
                settle(result.done ? "return" : "normal", arg1);
            }, function(err) {
                resume("throw", err);
            });
        } catch (err) {
            settle("throw", err);
        }
    }
    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);
};