sort-index.js

function sortedIndex(array, value, iterator, pivot) {
    var low = 0,
        high = array.length,
        target = iterator(value);
    while (low - pivot < high) {
      var mid = (((low + high) >>> 1) + pivot) % array.length;
      if (iterator(array[mid]) < target) low = mid + 1;
      else high = mid;
    }
    return low;
}