nodejs+express递归实现树形结构demo

# core-js [](https://gitter.im/zloirock/core-js?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [](https://www.npmjs.com/package/core-js) [](http://npm-stat.com/charts.html?package=core-js&author=&from=2014-11-18&to=2114-11-18) [](https://travis-ci.org/zloirock/core-js) [](https://david-dm.org/zloirock/core-js#info=devDependencies) Modular compact standard library for JavaScript. Includes polyfills for [ECMAScript 5](#ecmascript-5), [ECMAScript 6](#ecmascript-6): [symbols](#ecmascript-6-symbol), [collections](#ecmascript-6-collections), [iterators](#ecmascript-6-iterators), [promises](#ecmascript-6-promise), [ECMAScript 7 proposals](#ecmascript-7); [setImmediate](#setimmediate), [array generics](#mozilla-javascript-array-generics). Some additional features such as [dictionaries](#dict) or [extended partial application](#partial-application). You can require only standardized features polyfills, use features without global namespace pollution or create a custom build. [Example](http://goo.gl/mfHYm2): ```javascript Array.from(new Set([1, 2, 3, 2, 1])); // => [1, 2, 3] '*'.repeat(10); // => '**********' Promise.resolve(32).then(log); // => 32 setImmediate(log, 42); // => 42 ``` [Without global namespace pollution](http://goo.gl/WBhs43): ```javascript var core = require('core-js/library'); // With a modular system, otherwise use global `core` core.Array.from(new core.Set([1, 2, 3, 2, 1])); // => [1, 2, 3] core.String.repeat('*', 10); // => '**********' core.Promise.resolve(32).then(core.log); // => 32 core.setImmediate(core.log, 42); // => 42 ``` - [Usage](#usage) - [Basic](#basic) - [CommonJS](#commonjs) - [Custom build](#custom-build) - [Features](#features) - [ECMAScript 5](#ecmascript-5) - [ECMAScript 6](#ecmascript-6) - [ECMAScript 6: Object](#ecmascript-6-object) - [ECMAScript 6: Function](#ecmascript-6-function) - [ECMAScript 6: Array](#ecmascript-6-array) - [ECMAScript 6: String](#ecmascript-6-string) - [ECMAScript 6: RegExp](#ecmascript-6-regexp) - [ECMAScript 6: Number](#ecmascript-6-number) - [ECMAScript 6: Math](#ecmascript-6-math) - [ECMAScript 6: Symbol](#ecmascript-6-symbol) - [ECMAScript 6: Collections](#ecmascript-6-collections) - [ECMAScript 6: Iterators](#ecmascript-6-iterators) - [ECMAScript 6: Promise](#ecmascript-6-promise) - [ECMAScript 6: Reflect](#ecmascript-6-reflect) - [ECMAScript 7](#ecmascript-7) - [Mozilla JavaScript: Array generics](#mozilla-javascript-array-generics) - [Web standards](#web-standards) - [setTimeout / setInterval](#settimeout--setinterval) - [setImmediate](#setimmediate) - [Non-standard](#non-standard) - [Object](#object) - [Dict](#dict) - [Partial application](#partial-application) - [Number Iterator](#number-iterator) - [Escaping HTML](#escaping-html) - [delay](#delay) - [console](#console) - [Missing polyfills](#missing-polyfills) - [Changelog](./CHANGELOG.md) ## Usage ### Basic ``` npm i core-js bower install core.js ``` ```javascript // Default require('core-js'); // Without global namespace pollution var core = require('core-js/library'); // Shim only require('core-js/shim'); ``` If you need complete build for browser, use builds from `core-js/client` path: [default](https://raw.githack.com/zloirock/core-js/master/client/core.min.js), [without global namespace pollution](https://raw.githack.com/zloirock/core-js/master/client/library.min.js), [shim only](https://raw.githack.com/zloirock/core-js/master/client/shim.min.js). Warning: if you uses `core-js` with the extension of native objects, require all needed `core-js` modules at the beginning of entry point of your application, otherwise maybe conflicts. ### CommonJS You can require only needed modules. ```js require('core-js/es5'); // if you need support IE8- require('core-js/fn/set'); require('core-js/fn/array/from'); require('core-js/fn/array/find-index'); Array.from(new Set([1, 2, 3, 2, 1])); // => [1, 2, 3] [1, 2, NaN, 3, 4].findIndex(isNaN); // => 2 // or, w/o global namespace pollution: var core = require('core-js/library/es5'); // if you need support IE8- var Set = require('core-js/library/fn/set'); var from = require('core-js/library/fn/array/from'); var findIndex = require('core-js/library/fn/array/find-index'); from(new Set([1, 2, 3, 2, 1])); // => [1, 2, 3] findIndex([1, 2, NaN, 3, 4], isNaN); // => 2 ``` Available entry points for methods / constructors, as above examples, excluding features from [`es5`](#ecmascript-5) module (this module requires completely in ES3 environment before all other modules). Available namespaces: for example, `core-js/es6/array` (`core-js/library/es6/array`) contains all [ES6 `Array` features](#ecmascript-6-array), `core-js/es6` (`core-js/library/es6`) contains all ES6 features. ### Custom build ``` npm i core-js && cd node_modules/core-js && npm i npm run grunt build:core.dict,es6 -- --blacklist=es6.promise,es6.math --library=on --path=custom uglify ``` Where `core.dict` and `es6` are modules (namespaces) names, which will be added to the build, `es6.promise` and `es6.math` are modules (namespaces) names, which will be excluded from the build, `--library=on` is flag for build without global namespace pollution and `custom` is target file name. Available namespaces: for example, `es6.array` contains [ES6 `Array` features](#ecmascript-6-array), `es6` contains all modules whose names start with `es6`. Available custom build from js code (required `webpack`): ```js require('core-js/build')({ modules: ['es6', 'core.dict'], // modules / namespaces blacklist: ['es6.reflect'], // blacklist of modules / namespaces library: false, // flag for build without global namespace pollution }, function(err, code){ // callback // ... }); ``` ## Features: ### ECMAScript 5 Module [`es5`](https://github.com/zloirock/core-js/blob/v1.2.6/modules/es5.js), nothing new - without examples. ```javascript Object .create(proto | null, descriptors?) -> object .getPrototypeOf(object) -> proto | null .defineProperty(target, key, desc) -> target, cap for ie8- .defineProperties(target, descriptors) -> target, cap for ie8- .getOwnPropertyDescriptor(object, key) -> desc .getOwnPropertyNames(object) -> array .keys(object) -> array Array .isArray(var) -> bool #slice(start?, end?) -> array, fix for ie7- #join(string = ',') -> string, fix for ie7- #indexOf(var, from?) -> int #lastIndexOf(var, from?) -> int #every(fn(val, index, @), that) -> bool #some(fn(val, index, @), that) -> bool #forEach(fn(val, index, @), that) -> void #map(fn(val, index, @), that) -> array #filter(fn(val, index, @), that) -> array #reduce(fn(memo, val, index, @), memo?) -> var #reduceRight(fn(memo, val, index, @), memo?) -> var Function #bind(object, ...args) -> boundFn(...args) Date .now() -> int #toISOString() -> string ``` Some features moved to [another modules / namespaces](#ecmascript-6), but available as part of `es5` namespace too: ```js Object .seal(object) -> object, cap for ie8- .freeze(object) -> object, cap for ie8- .preventExtensions(object) -> object, cap for ie8- .isSealed(object) -> bool, cap for ie8- .isFrozen(object) -> bool, cap for ie8- .isExtensible(object) -> bool, cap for ie8- String #trim() -> str ``` ### ECMAScript 6 #### ECMAScript 6: Object Modules [`es6.object.assign`](https://github.com/zloirock/core-js/blob/v1.2.6/modules/es6.object.assign.js), [`es6.object.is`](https://github.com/zloirock/core-js/blob/v1.2.6/modu