quicksort in javascript

qs.js

//http://blog.mgechev.com/2012/11/24/javascript-sorting-performance-quicksort-v8/

function swap(array, i, j) {
  var temp = array[i];
  array[i] = array[j];
  array[j] = temp;
  return array;
}

function partition(array, left, right, comparitor) {
  var cmp = array[right - 1],
      minEnd = left,
      maxEnd;
  for (maxEnd = left; maxEnd < right - 1; maxEnd += 1) {
    //if (array[maxEnd] <= cmp) {
    if (comparitor(array[maxEnd], cmp) <= 0) {
      swap(array, maxEnd, minEnd);
      minEnd += 1;
    }
  }
  swap(array, minEnd, right - 1);
  return minEnd;
}

function quickSort(array, left, right, comparitor) {

  if (left < right) {
    var p = partition(array, left, right, comparitor);
    quickSort(array, left, p, comparitor);
    quickSort(array, p + 1, right, comparitor);
  }
  return array;
}

//don't use, native sort is 4x faster
function qs(array, comparitor) {
  return quickSort(array, 0, array.length, comparitor);
}