<?php
  
  namespace Illuminate\Contracts\Events;
  
  interface Dispatcher
  {
      /**
       * Register an event listener with the dispatcher.
       *
       * @param  string|array  $events
       * @param  \Closure|string  $listener
       * @return void
       */
      public function listen($events, $listener);
  
      /**
       * Determine if a given event has listeners.
       *
       * @param  string  $eventName
       * @return bool
       */
      public function hasListeners($eventName);
  
      /**
       * Register an event subscriber with the dispatcher.
       *
       * @param  object|string  $subscriber
       * @return void
       */
      public function subscribe($subscriber);
  
      /**
       * Dispatch an event until the first non-null response is returned.
       *
       * @param  string|object  $event
       * @param  mixed  $payload
       * @return array|null
       */
      public function until($event, $payload = []);
  
      /**
       * Dispatch an event and call the listeners.
       *
       * @param  string|object  $event
       * @param  mixed  $payload
       * @param  bool  $halt
       * @return array|null
       */
      public function dispatch($event, $payload = [], $halt = false);
  
      /**
       * Register an event and payload to be fired later.
       *
       * @param  string  $event
       * @param  array  $payload
       * @return void
       */
      public function push($event, $payload = []);
  
      /**
       * Flush a set of pushed events.
       *
       * @param  string  $event
       * @return void
       */
      public function flush($event);
  
      /**
       * Remove a set of listeners from the dispatcher.
       *
       * @param  string  $event
       * @return void
       */
      public function forget($event);
  
      /**
       * Forget all of the queued listeners.
       *
       * @return void
       */
      public function forgetPushed();
  }