Binary search implementation for JS arrays

JS array binary search

/**
 * Taken from http://www.dweebd.com/javascript/binary-search-an-array-in-javascript/
 */
Array.prototype.find = function (needle, comparator) {
  var low = 0,
      high = this.length - 1,
      i,
      comparison;
  while (low <= high) {
    i = Math.floor((low + high) / 2);
    comparison = comparator(this[i], needle);
    if (comparison < 0) {
      low = i + 1; continue;
    }
    if (comparison > 0) {
      high = i - 1; continue;
    }
    return i;
  }
  return -1;
};

// sample call
'abcdefghijklmnopqrstuvwxyz'.split('').find('l', function (current, needle) {
  return current.toLowerCase().localeCompare(needle.toLowerCase());
});