<?php
 
 namespace Illuminate\Contracts\Events;
 
 interface Dispatcher
 {
     /**
      * Register an event listener with the dispatcher.
      *
      * @param  string|array  $events
      * @param  mixed  $listener
      * @return void
      */
     public function listen($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();
 }