lodash/array/pullAt.js

import baseAt from '../internal/baseAt';
import baseCompareAscending from '../internal/baseCompareAscending';
import baseFlatten from '../internal/baseFlatten';
import isIndex from '../internal/isIndex';
import restParam from '../function/restParam';

/** Used for native method references. */
var arrayProto = Array.prototype;

/** Native method references. */
var splice = arrayProto.splice;

/**
 * Removes elements from `array` corresponding to the given indexes and returns
 * an array of the removed elements. Indexes may be specified as an array of
 * indexes or as individual arguments.
 *
 * **Note:** Unlike `_.at`, this method mutates `array`.
 *
 * @static
 * @memberOf _
 * @category Array
 * @param {Array} array The array to modify.
 * @param {...(number|number[])} [indexes] The indexes of elements to remove,
 *  specified as individual indexes or arrays of indexes.
 * @returns {Array} Returns the new array of removed elements.
 * @example
 *
 * var array = [5, 10, 15, 20];
 * var evens = _.pullAt(array, 1, 3);
 *
 * console.log(array);
 * // => [5, 15]
 *
 * console.log(evens);
 * // => [10, 20]
 */
var pullAt = restParam(function(array, indexes) {
  array || (array = []);
  indexes = baseFlatten(indexes);

  var length = indexes.length,
      result = baseAt(array, indexes);

  indexes.sort(baseCompareAscending);
  while (length--) {
    var index = parseFloat(indexes[length]);
    if (index != previous && isIndex(index)) {
      var previous = index;
      splice.call(array, index, 1);
    }
  }
  return result;
});

export default pullAt;