forked from M3-Academy/challenge-algorithms-v2.0
77 lines
2.0 KiB
JavaScript
77 lines
2.0 KiB
JavaScript
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'use strict';
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Object.defineProperty(exports, '__esModule', {
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value: true
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});
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exports.default = deepCyclicCopy;
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/**
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* Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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const EMPTY = new Set();
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function deepCyclicCopy(
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value,
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options = {
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blacklist: EMPTY,
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keepPrototype: false
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},
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cycles = new WeakMap()
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) {
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if (typeof value !== 'object' || value === null || Buffer.isBuffer(value)) {
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return value;
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} else if (cycles.has(value)) {
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return cycles.get(value);
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} else if (Array.isArray(value)) {
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return deepCyclicCopyArray(value, options, cycles);
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} else {
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return deepCyclicCopyObject(value, options, cycles);
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}
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}
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function deepCyclicCopyObject(object, options, cycles) {
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const newObject = options.keepPrototype
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? Object.create(Object.getPrototypeOf(object))
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: {};
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const descriptors = Object.getOwnPropertyDescriptors(object);
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cycles.set(object, newObject);
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Object.keys(descriptors).forEach(key => {
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if (options.blacklist && options.blacklist.has(key)) {
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delete descriptors[key];
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return;
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}
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const descriptor = descriptors[key];
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if (typeof descriptor.value !== 'undefined') {
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descriptor.value = deepCyclicCopy(
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descriptor.value,
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{
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blacklist: EMPTY,
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keepPrototype: options.keepPrototype
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},
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cycles
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);
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}
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descriptor.configurable = true;
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});
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return Object.defineProperties(newObject, descriptors);
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}
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function deepCyclicCopyArray(array, options, cycles) {
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const newArray = options.keepPrototype
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? new (Object.getPrototypeOf(array).constructor)(array.length)
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: [];
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const length = array.length;
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cycles.set(array, newArray);
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for (let i = 0; i < length; i++) {
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newArray[i] = deepCyclicCopy(
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array[i],
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{
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blacklist: EMPTY,
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keepPrototype: options.keepPrototype
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},
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cycles
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);
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}
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return newArray;
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}
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