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Diffstat (limited to 'node_modules/async/transform.js')
-rw-r--r-- | node_modules/async/transform.js | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/node_modules/async/transform.js b/node_modules/async/transform.js new file mode 100644 index 000000000..e80d1ee51 --- /dev/null +++ b/node_modules/async/transform.js @@ -0,0 +1,85 @@ +'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); + +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 {Function} iteratee - A function applied to each item in the + * collection that potentially modifies the accumulator. The `iteratee` is + * passed a `callback(err)` which accepts an optional error as its first + * argument. If an error is passed to the callback, the transform is stopped + * and the main `callback` is immediately called with the error. + * 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); + + (0, _eachOf2.default)(coll, function (v, k, cb) { + iteratee(accumulator, v, k, cb); + }, function (err) { + callback(err, accumulator); + }); +} +module.exports = exports['default'];
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