lodash/internal/baseWhile.js

define(['./baseSlice'], function(baseSlice) {

  /**
   * The base implementation of `_.dropRightWhile`, `_.dropWhile`, `_.takeRightWhile`,
   * and `_.takeWhile` without support for callback shorthands and `this` binding.
   *
   * @private
   * @param {Array} array The array to query.
   * @param {Function} predicate The function invoked per iteration.
   * @param {boolean} [isDrop] Specify dropping elements instead of taking them.
   * @param {boolean} [fromRight] Specify iterating from right to left.
   * @returns {Array} Returns the slice of `array`.
   */
  function baseWhile(array, predicate, isDrop, fromRight) {
    var length = array.length,
        index = fromRight ? length : -1;

    while ((fromRight ? index-- : ++index < length) && predicate(array[index], index, array)) {}
    return isDrop
      ? baseSlice(array, (fromRight ? 0 : index), (fromRight ? index + 1 : length))
      : baseSlice(array, (fromRight ? index + 1 : 0), (fromRight ? length : index));
  }

  return baseWhile;
});