Non Repeating Random Number Utility, with loop callback and end-to-end elimination

nonRepRand.js

/*

Create a new nonRepRand instance like this, you can have multiple, just use a diff variable name:
var numberGenerator = new nonRepRand(1,5);

use the .next() method to get the next number, see example below

.next() method, can take a callback which will fire when the nonRepRand generator loops around the set, ie. if nonRepRand(1,5), .next(callBack) will fire the callback after generating it's 5th value, the callback will be passed a value of true.

nonRepRand() will never give you end to end repeating numbers. for example if the 5th value of the set is a "3" and the first value of the next loop is a "3", nonRepRand will automatically get you a new value instead of a "3", so the values can never be next to one another.

 */

var nonRepRand = function(low, high){

  function range(start, end) {
		var foo = [];
		for (var i = start; i <= end; i++) {
				foo.push(i);
		}
		return foo;
  }

  function shuffle(o){ //v1.0 - google labs
		for(var j, x, i = o.length; i; j = parseInt(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);
		return o;
  }

  this.low = low;
  this.high = high;
  this.numberSet = shuffle(range( this.low, this.high));
  this.pop
  this.prev

  // console.log(this.numberSet);

  this.next = function(loopCallback){
    this.prev = this.pop;
    this.pop = this.numberSet.shift()

    if(this.pop == undefined){ //have we reached the end?
      if(loopCallback != null){
        loopCallback(true);
      }

      this.numberSet = shuffle(range( this.low, this.high)); //get a new numberset
      // console.log(this.numberSet);

      this.pop = this.numberSet.shift() //get the first val from the new numberset

      if(this.pop == this.prev){ //is the first val of the new numberset the same as the previous?
        this.numberSet.push(this.pop) //move it to the front of the array
        // console.log("moved " + this.pop + " to back of the array");
        this.pop = this.numberSet.shift() //get the second value instead
      }

    }

    return this.pop;
  }

}


/* +~+~+~+~+~+~+~+~+~+~+~+~+~+~+ Render some thigs to the Console +~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+~+ */

var numberGenerator = new nonRepRand(1,5); //create a new nonRepRand generator

setInterval(function(){
  console.log( numberGenerator.next(cb) );
}, 600)

function cb(loop){
console.log("Loopcallback working! " + loop);
}