Detailed explanation of operator overloading in Javascript

/**
 * 转换方法
 * @param a
 * @param op
 * @param b
 * @returns {*}
 * @private
 */
export function __replace__(a,op,b){
  if(typeof(a) != 'object' && typeof(b) != 'object'){
    return new Function('a','b','return a' + op + 'b')(a,b)
  }
  if(!Object.getPrototypeOf(a).isPrototypeOf(b)
    && Object.getPrototypeOf(b).isPrototypeOf(a)){
    throw '不同类型的对象不能使用四则运算'
  }
  let target = null
  if (Object.getPrototypeOf(a).isPrototypeOf(b)) {
    target = new Function('return ' + b.__proto__.constructor.name)()
  }
  if (Object.getPrototypeOf(b).isPrototypeOf(a)) {
    target = new Function('return ' + a.__proto__.constructor.name)()
  }
  if (op == '+') {
    if (target.__add__ != undefined) {
      return target.__add__(a, b)
    }else {
      throw target.toString() +'\n未定义__add__方法'
    }
  }else if(op == '-') {
    if (target.__plus__ != undefined) {
      return target.__plus__(a, b)
    }else {
      throw target.toString() + '\n未定义__plus__方法'
    }
  }else if(op == '*') {
    if (target.__multiply__ != undefined) {
      return target.__multiply__(a, b)
    }else {
      throw target.toString() + '\n未定义__multiply__方法'
    }
  } else if (op == '/') {
    if (target.__pide__ != undefined) {
      return target.__pide__(a, b)
    }else {
      throw target.toString() + '\n未定义__pide__方法'
    }
  } else if (op == '%') {
    if (target.__mod__ != undefined) {
      return target.__mod__(a, b)
    }else {
      throw target.toString() + '\n未定义__mod__方法'
    }
  } else if(op == '.*') {
    if (target.__dot_multiply__ != undefined) {
      return target.__dot_multiply__(a, b)
    }else {
      throw target.toString() + '\n未定义__dot_multiply__方法'
    }
  } else if(op == './') {
    if (target.__dot_pide__ != undefined) {
      return target.__dot_pide__(a, b)
    }else {
      throw target.toString() + '\n未定义__dot_pide__方法'
    }
  } else if(op == '**') {
    if (target.__power__ != undefined) {
      return target.__power__(a, b)
    }else {
      throw target.toString() + '\n未定义__power__方法'
    }
  }else {
    throw op + '运算符无法识别'
  }
}

/**
 * 表达式转换工具方法
 * @param code
 */
export function translate (code) {
  let data = []
  let tmp_code = code.replace(/\s/g,'')
  let tmp = []
  let vari = tmp_code.split(/["]+[^"]*["]+|[&#39;]+[^&#39;]*[&#39;]+|\*\*|\+|-|\*|\/|\(|\)|\?|>[=]|<[=]|={2}|:|&{2}|\|{2}|\{|\}|=|%|\.\/|\.\*|,/g)
  let ops = tmp_code.match(/["]+[^"]*["]+|[&#39;]+[^&#39;]*[&#39;]+|\*\*|\+|-|\*|\/|\(|\)|\?|>[=]|<[=]|={2}|:|&{2}|\|{2}|\{|\}|=|%|\.\/|\.\*|,/g)
  for (let i = 0,len = ops.length; i < len; i++) {
    if (vari[i] != &#39;&#39;) {
      tmp.push(vari[i])
    }
    if (ops[i] != &#39;&#39;) {
      tmp.push(ops[i])
    }
  }
  tmp.push(vari[ops.length])
  for (let i = 0; i < tmp.length; i++){
    let item = tmp[i]
    if(/\*\*|\+|-|\*|\/|%|\.\/|\.\*/.test(tmp[i])) {
      let top = data.pop()
      let trans = &#39;__replace__(&#39; + top + &#39;,\&#39;&#39; + tmp[i] + &#39;\&#39;,&#39;
      data.push(trans)
    }else{
      if (&#39;)&#39; == tmp[i]) {
        let trans0 = tmp[i]
        let top0 = data.pop()
        while (top0 != &#39;(&#39;) {
          trans0 = top0 + trans0
          top0 = data.pop()
        }
        trans0 = top0 + trans0
        let pre = data[data.length - 1]
        while(/[_\w]+[\.]?[_\w]+/.test(pre)
        && !/^__replace__\(/.test(pre)
        && pre != undefined) {
          pre = data.pop()
          trans0 = pre + trans0
          pre = data[data.length - 1]
        }
        pre = data[data.length - 1]
        while(pre != undefined
        && /^__replace__\(/.test(pre)){
          pre = data.pop()
          trans0 = pre + trans0 + &#39;)&#39;
          pre = data[data.length - 1]
        }
        data.push(trans0)
      }else {
        let pre = data[data.length - 1]
        let trans1 = tmp[i]
        while(pre != undefined
        && /^__replace__\(/.test(pre)
        && !/\*\*|\+|-|\*|\/|\(|\?|>[=]|<[=]|={2}|:|&{2}|\|{2}|\{|=|\}|%|\.\/|\.\*/.test(item)
        && !/^__replace__\(/.test(item)) {
          if(tmp[i + 1] == undefined){
            pre = data.pop()
            trans1 = pre + trans1 + &#39;)&#39;
            break;
          }else{
            pre = data.pop()
            trans1 = pre + trans1 + &#39;)&#39;
            pre = data[data.length - 1]
          }

        }
        data.push(trans1)

      }
    }
  }
  let result = &#39;&#39;
  data.forEach((value, key, own) => {
    result += value
  })
  return result
}

export default class OOkay {
  constructor () {
    let protos = Object.getOwnPropertyNames(Object.getPrototypeOf(this))
    protos.forEach((proto, key, own) => {
      if(proto != 'constructor'){
        Object.defineProperty(this, proto, {
          value:new Function(translate_block(proto, this[proto].toString())).call(this)
        })
      }
    })
  }
}

/**
 * 类代码块转换工具
 * @param name
 * @param block
 * @returns {string}
 */
export function translate_block (name , block) {
  let codes = block.split('\n')
  let reg = new RegExp('^' + name + '$')
  console.log(reg.source)
  codes[0] = codes[0].replace(name,'function')
  for(let i = 1; i < codes.length; i++) {
    if (codes[i].indexOf(&#39;//&#39;) != -1) {
      codes[i] = codes[i].substring(0,codes[i].indexOf(&#39;//&#39;))
    }
    if(/\*\*|\+|-|\*|\/|%|\.\/|\.\*/g.test(codes[i])){
      if (codes[i].indexOf(&#39;return &#39;) != -1) {
        let ret_index = codes[i].indexOf(&#39;return &#39;) + 7
        codes[i] = codes[i].substring(0,ret_index) + translate(codes[i].substring(ret_index))
      }else {
        let eq_index = codes[i].indexOf(&#39;=&#39;) + 1
        codes[i] = codes[i].substring(0,eq_index) + translate(codes[i].substring(eq_index))
      }
    }
  }
  return &#39;return &#39; + codes.join(&#39;\n&#39;)
}

/**
   * 非继承类的注入方法
   * @param target
   */
  static inject (target) {
    let protos = Object.getOwnPropertyNames(Object.getPrototypeOf(target))
    protos.forEach((proto, key, own) => {
      if (proto != 'constructor') {
        Object.defineProperty(target, proto, {
          value:new Function(translate_block(proto, target[proto].toString())).call(target)
        })
      }
    })
  }

static __$__(fn) {
    if(!(fn instanceof Function)){
      throw '参数错误'
    }
    (new Function(translate_block('function',fn.toString()))).call(window)()
  }