lodash/lodash._binaryindex/index.js

/**
 * lodash 3.0.1 (Custom Build) <https://lodash.com/>
 * Build: `lodash modern modularize exports="npm" -o ./`
 * Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license <https://lodash.com/license>
 */
var binaryIndexBy = require('lodash._binaryindexby');

/** Used as references for the maximum length and index of an array. */
var MAX_ARRAY_LENGTH = 4294967295,
    HALF_MAX_ARRAY_LENGTH = MAX_ARRAY_LENGTH >>> 1;

/**
 * Performs a binary search of `array` to determine the index at which `value`
 * should be inserted into `array` in order to maintain its sort order.
 *
 * @private
 * @param {Array} array The sorted array to inspect.
 * @param {*} value The value to evaluate.
 * @param {boolean} [retHighest] Specify returning the highest qualified index.
 * @returns {number} Returns the index at which `value` should be inserted
 *  into `array`.
 */
function binaryIndex(array, value, retHighest) {
  var low = 0,
      high = array ? array.length : low;

  if (typeof value == 'number' && value === value && high <= HALF_MAX_ARRAY_LENGTH) {
    while (low < high) {
      var mid = (low + high) >>> 1,
          computed = array[mid];

      if ((retHighest ? (computed <= value) : (computed < value)) && computed !== null) {
        low = mid + 1;
      } else {
        high = mid;
      }
    }
    return high;
  }
  return binaryIndexBy(array, value, identity, retHighest);
}

/**
 * This method returns the first argument provided to it.
 *
 * @static
 * @memberOf _
 * @category Utility
 * @param {*} value Any value.
 * @returns {*} Returns `value`.
 * @example
 *
 * var object = { 'user': 'fred' };
 *
 * _.identity(object) === object;
 * // => true
 */
function identity(value) {
  return value;
}

module.exports = binaryIndex;