var serialOrdered = require('../serialOrdered.js');
  
  // API
  module.exports = ReadableSerialOrdered;
  // expose sort helpers
  module.exports.ascending  = serialOrdered.ascending;
  module.exports.descending = serialOrdered.descending;
  
  /**
   * Streaming wrapper to `asynckit.serialOrdered`
   *
   * @param   {array|object} list - array or object (named list) to iterate over
   * @param   {function} iterator - iterator to run
   * @param   {function} sortMethod - custom sort function
   * @param   {function} callback - invoked when all elements processed
   * @returns {stream.Readable#}
   */
  function ReadableSerialOrdered(list, iterator, sortMethod, callback)
  {
    if (!(this instanceof ReadableSerialOrdered))
    {
      return new ReadableSerialOrdered(list, iterator, sortMethod, callback);
    }
  
    // turn on object mode
    ReadableSerialOrdered.super_.call(this, {objectMode: true});
  
    this._start(serialOrdered, list, iterator, sortMethod, callback);
  }