define(['../internal/arrayEach', '../internal/baseCallback', '../internal/baseCreate', '../internal/baseForOwn', '../lang/isArray', '../lang/isObject', '../lang/isTypedArray'], function(arrayEach, baseCallback, baseCreate, baseForOwn, isArray, isObject, isTypedArray) { /** * An alternative to `_.reduce`; this method transforms `object` to a new * `accumulator` object which is the result of running each of its own enumerable * properties through `iteratee`, with each invocation potentially mutating * the `accumulator` object. The `iteratee` is bound to `thisArg` and invoked * with four arguments; (accumulator, value, key, object). Iterator functions * may exit iteration early by explicitly returning `false`. * * @static * @memberOf _ * @category Object * @param {Array|Object} object The object to iterate over. * @param {Function} [iteratee=_.identity] The function invoked per iteration. * @param {*} [accumulator] The custom accumulator value. * @param {*} [thisArg] The `this` binding of `iteratee`. * @returns {*} Returns the accumulated value. * @example * * var squares = _.transform([1, 2, 3, 4, 5, 6], function(result, n) { * n *= n; * if (n % 2) { * return result.push(n) < 3; * } * }); * // => [1, 9, 25] * * var mapped = _.transform({ 'a': 1, 'b': 2, 'c': 3 }, function(result, n, key) { * result[key] = n * 3; * }); * // => { 'a': 3, 'b': 6, 'c': 9 } */ function transform(object, iteratee, accumulator, thisArg) { var isArr = isArray(object) || isTypedArray(object); iteratee = baseCallback(iteratee, thisArg, 4); if (accumulator == null) { if (isArr || isObject(object)) { var Ctor = object.constructor; if (isArr) { accumulator = isArray(object) ? new Ctor : []; } else { accumulator = baseCreate(typeof Ctor == 'function' && Ctor.prototype); } } else { accumulator = {}; } } (isArr ? arrayEach : baseForOwn)(object, function(value, index, object) { return iteratee(accumulator, value, index, object); }); return accumulator; } return transform; });