如何将长整数转换成链并进行运算？

Question

如何将长整数转换成链并进行运算？ 解决这个问题的方法可能是使用bigint库：“ big-integer”。

加载库：

var bigInt = require("big-integer");

String.prototype.add = function(val){        
    var x = this;
    var y = val;
    var result = "";
    var len;
    var lenx = x.length;
    var leny = y.length;
    var x1,y1,rem,div=0;

    if(lenx>leny) len = lenx; else len = leny;
    for(var i=0;i<len;i++){
        if(i>=lenx) x1  = 0;
        else x1 = parseInt(x[lenx-i-1]);
        if(i>=leny) y1 = 0;
        else y1 = parseInt(y[leny-i-1]);
        rem = (x1+y1+div)%10;
        div = Math.floor((x1 + y1+div)/10);
        result = rem + result;
    }
    if(div>0){
        result = div + result;
    }
    return result;  
}
String.prototype.minus = function(val){
    var vf = this.toString();
    var val_ini =bigInt(val);
    var val_fin =bigInt(vf);
    var result = val_fin.minus(val_ini);
    return result.toJSNumber();
}

示例：

var binary = '101111010110011011100100';
var binaryText = bigInt(binary);//Data converted to String
//Make addition
binaryText.add("1");
//Make substract
binaryText.min("1");