|
|
- 'use strict';
-
- Object.defineProperty(exports, "__esModule", {
- value: true
- });
- exports.default = transform;
-
- var _isArray = require('lodash/isArray');
-
- var _isArray2 = _interopRequireDefault(_isArray);
-
- var _noop = require('lodash/noop');
-
- var _noop2 = _interopRequireDefault(_noop);
-
- var _eachOf = require('./eachOf');
-
- var _eachOf2 = _interopRequireDefault(_eachOf);
-
- var _once = require('./internal/once');
-
- var _once2 = _interopRequireDefault(_once);
-
- var _wrapAsync = require('./internal/wrapAsync');
-
- var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
-
- function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
-
- /**
- * A relative of `reduce`. Takes an Object or Array, and iterates over each
- * element in series, each step potentially mutating an `accumulator` value.
- * The type of the accumulator defaults to the type of collection passed in.
- *
- * @name transform
- * @static
- * @memberOf module:Collections
- * @method
- * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
- * @param {*} [accumulator] - The initial state of the transform. If omitted,
- * it will default to an empty Object or Array, depending on the type of `coll`
- * @param {AsyncFunction} iteratee - A function applied to each item in the
- * collection that potentially modifies the accumulator.
- * Invoked with (accumulator, item, key, callback).
- * @param {Function} [callback] - A callback which is called after all the
- * `iteratee` functions have finished. Result is the transformed accumulator.
- * Invoked with (err, result).
- * @example
- *
- * async.transform([1,2,3], function(acc, item, index, callback) {
- * // pointless async:
- * process.nextTick(function() {
- * acc.push(item * 2)
- * callback(null)
- * });
- * }, function(err, result) {
- * // result is now equal to [2, 4, 6]
- * });
- *
- * @example
- *
- * async.transform({a: 1, b: 2, c: 3}, function (obj, val, key, callback) {
- * setImmediate(function () {
- * obj[key] = val * 2;
- * callback();
- * })
- * }, function (err, result) {
- * // result is equal to {a: 2, b: 4, c: 6}
- * })
- */
- function transform(coll, accumulator, iteratee, callback) {
- if (arguments.length <= 3) {
- callback = iteratee;
- iteratee = accumulator;
- accumulator = (0, _isArray2.default)(coll) ? [] : {};
- }
- callback = (0, _once2.default)(callback || _noop2.default);
- var _iteratee = (0, _wrapAsync2.default)(iteratee);
-
- (0, _eachOf2.default)(coll, function (v, k, cb) {
- _iteratee(accumulator, v, k, cb);
- }, function (err) {
- callback(err, accumulator);
- });
- }
- module.exports = exports['default'];
|