remove.js

var baseCallback = require('../internal/baseCallback'),
    basePullAt = require('../internal/basePullAt');

/**
 * Removes all elements from `array` that `predicate` returns truthy for
 * and returns an array of the removed elements. The predicate is bound to
 * `thisArg` and invoked with three arguments: (value, index, array).
 *
 * If a property name is provided for `predicate` the created `_.property`
 * style callback returns the property value of the given element.
 *
 * If a value is also provided for `thisArg` the created `_.matchesProperty`
 * style callback returns `true` for elements that have a matching property
 * value, else `false`.
 *
 * If an object is provided for `predicate` the created `_.matches` style
 * callback returns `true` for elements that have the properties of the given
 * object, else `false`.
 *
 * **Note:** Unlike `_.filter`, this method mutates `array`.
 *
 * @static
 * @memberOf _
 * @category Array
 * @param {Array} array The array to modify.
 * @param {Function|Object|string} [predicate=_.identity] The function invoked
 *  per iteration.
 * @param {*} [thisArg] The `this` binding of `predicate`.
 * @returns {Array} Returns the new array of removed elements.
 * @example
 *
 * var array = [1, 2, 3, 4];
 * var evens = _.remove(array, function(n) {
 *   return n % 2 == 0;
 * });
 *
 * console.log(array);
 * // => [1, 3]
 *
 * console.log(evens);
 * // => [2, 4]
 */
function remove(array, predicate, thisArg) {
  var result = [];
  if (!(array && array.length)) {
    return result;
  }
  var index = -1,
      indexes = [],
      length = array.length;

  predicate = baseCallback(predicate, thisArg, 3);
  while (++index < length) {
    var value = array[index];
    if (predicate(value, index, array)) {
      result.push(value);
      indexes.push(index);
    }
  }
  basePullAt(array, indexes);
  return result;
}

module.exports = remove;