This is a simple class for calculating the sliding window of a hex string.
npm install hex-window --save
var HexWindow = require("hex-window");
// Initialize HexWindow with a starting string and a "resolution" consisting of zeros and ones only
// which denotes the amount to slide the window by.
var hexwindow = new HexWindow("ffffffffffffffffffffffffffffffff","10000000000000000000000000000000");
var results = hexwindow.back();
// results contains {"upper":"ffffffffffffffffffffffffffffffff","lower","efffffffffffffffffffffffffffffff"}
You can also widen or narrow the window via the .narrow() and .widen() functions.