1  'use strict';
 2  
 3  Object.defineProperty(exports, "__esModule", {
 4      value: true
 5  });
 6  
 7  var _wrapAsync = require('./internal/wrapAsync');
 8  
 9  var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
10  
11  var _mapLimit = require('./mapLimit');
12  
13  var _mapLimit2 = _interopRequireDefault(_mapLimit);
14  
15  var _awaitify = require('./internal/awaitify');
16  
17  var _awaitify2 = _interopRequireDefault(_awaitify);
18  
19  function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
20  
21  /**
22   * The same as [`concat`]{@link module:Collections.concat} but runs a maximum of `limit` async operations at a time.
23   *
24   * @name concatLimit
25   * @static
26   * @memberOf module:Collections
27   * @method
28   * @see [async.concat]{@link module:Collections.concat}
29   * @category Collection
30   * @alias flatMapLimit
31   * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
32   * @param {number} limit - The maximum number of async operations at a time.
33   * @param {AsyncFunction} iteratee - A function to apply to each item in `coll`,
34   * which should use an array as its result. Invoked with (item, callback).
35   * @param {Function} [callback] - A callback which is called after all the
36   * `iteratee` functions have finished, or an error occurs. Results is an array
37   * containing the concatenated results of the `iteratee` function. Invoked with
38   * (err, results).
39   * @returns A Promise, if no callback is passed
40   */
41  function concatLimit(coll, limit, iteratee, callback) {
42      var _iteratee = (0, _wrapAsync2.default)(iteratee);
43      return (0, _mapLimit2.default)(coll, limit, (val, iterCb) => {
44          _iteratee(val, (err, ...args) => {
45              if (err) return iterCb(err);
46              return iterCb(err, args);
47          });
48      }, (err, mapResults) => {
49          var result = [];
50          for (var i = 0; i < mapResults.length; i++) {
51              if (mapResults[i]) {
52                  result = result.concat(...mapResults[i]);
53              }
54          }
55  
56          return callback(err, result);
57      });
58  }
59  exports.default = (0, _awaitify2.default)(concatLimit, 4);
60  module.exports = exports['default'];