zorgick

/**
 *
 * @param {Object} obj source object to be traversed
 * @param {RegExp} fieldName regular expression that represents a required property
 */
export const getFieldValues = (obj, fieldName) => {
  if (Object.keys(obj).length === 0) {
    return
  }

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/**
 * MyNewType definition
 * @typedef {MyNewType} MyNewType
 * @param {number} first
 * @param {number} second
 * @property {function} logFirst
 * @property {function} logSecond
 * @returns MyNewType
 */

zorgick

detectBrowserlanguage(defaultLang) {
    const navLang = navigator.language || navigator.userLanguage || defaultLang;
    return navLang.substring(0, 2);
}

componentDidMount() {
    const defaultLang = this.detectBrowserlanguage("en");
    const lang = localStorage.getItem("user-lang");
    const usedLang = lang ? lang : defaultLang;

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/**
 * This function accepts array of strings or strings or both
 * all empty or falsy values are omitted
 * returns a string of classes
 *@example
 // 1) simple use case: single argument - array of strings
    stringifyClasses([
        styles.day,
        isPassive && styles.dayPassive,
        disabled && styles.dayDisabled,

zorgick

How to install tikz-uml package on Mac

#!/bin/sh

mkdir -p ~/Library/texmf/tex/latex/tikz-uml/ # It doesn't really matter where to save this file 

cp ~/Downloads/tikzuml-v1.0b/tikz-uml.sty ~/Library/texmf/tex/latex/tikz-uml/

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% Preamble
\usepackage{tikz-uml}
\usetikzlibrary{positioning}
% Preamble end
...
\begin{tikzpicture}[shorten >=1pt,node distance=3cm,auto]%,on grid
\tikzstyle{state}=[shape=circle,thick,draw,minimum size=1.5cm]

  \node[state] (A1) {$A_1$};
  \node[state,above of=A1] (B1) {$B_1$};

zorgick

DOM Performance

• How the browser renders the document
  • Receives the data (bytes) from the server.
  • Parses and converts into tokens (<, TagName, Attribute, AttributeValue, >).
  • Turns tokens into nodes.
  • Turns nodes into the DOM tree.
• Builds CSSOM tree from the css rules.

zorgick

// 通过 typeof 来查看每种数据类型的描述
// [undefined, null, true, '', 0, Symbol(), {}].map(it => typeof it)
// ["undefined", "object", "boolean", "string", "number", "symbol", "object"]


function clone(obj) {
  // 添加一个 WeakMap 来记录已经拷贝过的对象，如果当前对象已经被拷贝过，那么直接从 WeakMap 中取出，否则重新创建一个对象并加入 WeakMap 中
  //  ES6 推出的 WeakMap 对象，该对象是一组键/值对的集合，其中的键是弱引用的。其键必须是对象，而值可以是任意的
  let map = new WeakMap();
  function deep(data) {

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// A state machine that works from a description including explicit transitions,
// and can generate a transition map and a digraph

const STATES = Symbol("states");
const STARTING_STATE = Symbol("starting-state");
const TRANSITIONS = Symbol("transitions");
const RESERVED = [STARTING_STATE, TRANSITIONS];

const MACHINES_TO_CURRENT_STATE_NAMES = new WeakMap();
const MACHINES_TO_STARTING_STATES = new WeakMap();

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/**
 * Ultimate version solving circular dependency with weakMap
 * Problems:
 * 1. Symbols not covered
 *
 * @param {Object} sourceObj
 * @param {WeakMap} [hash=new WeakMap()]
 * @returns
 */
var deepCloneUltimate = (sourceObj, hash = new WeakMap()) => {