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- var arrayEach = require('./_arrayEach'),
- baseCreate = require('./_baseCreate'),
- baseForOwn = require('./_baseForOwn'),
- baseIteratee = require('./_baseIteratee'),
- getPrototype = require('./_getPrototype'),
- isArray = require('./isArray'),
- isBuffer = require('./isBuffer'),
- isFunction = require('./isFunction'),
- isObject = require('./isObject'),
- isTypedArray = require('./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 string keyed properties thru `iteratee`, with each invocation
- * potentially mutating the `accumulator` object. If `accumulator` is not
- * provided, a new object with the same `[[Prototype]]` will be used. The
- * iteratee is invoked with four arguments: (accumulator, value, key, object).
- * Iteratee functions may exit iteration early by explicitly returning `false`.
- *
- * @static
- * @memberOf _
- * @since 1.3.0
- * @category Object
- * @param {Object} object The object to iterate over.
- * @param {Function} [iteratee=_.identity] The function invoked per iteration.
- * @param {*} [accumulator] The custom accumulator value.
- * @returns {*} Returns the accumulated value.
- * @example
- *
- * _.transform([2, 3, 4], function(result, n) {
- * result.push(n *= n);
- * return n % 2 == 0;
- * }, []);
- * // => [4, 9]
- *
- * _.transform({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
- * (result[value] || (result[value] = [])).push(key);
- * }, {});
- * // => { '1': ['a', 'c'], '2': ['b'] }
- */
- function transform(object, iteratee, accumulator) {
- var isArr = isArray(object),
- isArrLike = isArr || isBuffer(object) || isTypedArray(object);
- iteratee = baseIteratee(iteratee, 4);
- if (accumulator == null) {
- var Ctor = object && object.constructor;
- if (isArrLike) {
- accumulator = isArr ? new Ctor : [];
- }
- else if (isObject(object)) {
- accumulator = isFunction(Ctor) ? baseCreate(getPrototype(object)) : {};
- }
- else {
- accumulator = {};
- }
- }
- (isArrLike ? arrayEach : baseForOwn)(object, function(value, index, object) {
- return iteratee(accumulator, value, index, object);
- });
- return accumulator;
- }
- module.exports = transform;
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