<?php
 
namespace Phug\Event;
 
class ListenerQueue extends \SplPriorityQueue
{
    public function compare($priority, $priorityToCompare)
    {
        if ($priority === $priorityToCompare) {
            return 0;
        }
 
        return $priority > $priorityToCompare ? -1 : 1;
    }
 
    public function insert($value, $priority)
    {
        if (!is_callable($value)) {
            $previous = null;
 
            try {
                if (is_array($value) || $value instanceof \Traversable) {
                    return $this->insertMultiple($value, $priority);
                }
            } catch (\InvalidArgumentException $multipleInsertException) {
                $previous = $multipleInsertException;
            }
 
            throw new \InvalidArgumentException(
                'Callback inserted into ListenerQueue needs to be callable',
                1,
                $previous
            );
        }
 
        parent::insert($value, $priority);
    }
 
    public function insertMultiple($value, $priority)
    {