| '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']; |