<?php

/*
 * This file is part of Twig.
 *
 * (c) 2009 Fabien Potencier
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
abstract class Twig_Extension implements Twig_ExtensionInterface
{
  /**
   * Initializes the runtime environment.
   *
   * This is where you can load some file that contains filter functions for instance.
   *
   * @param Twig_Environment $environment The current Twig_Environment instance
   */
  public function initRuntime(Twig_Environment $environment) {}

  /**
   * Returns the token parser instances to add to the existing list.
   *
   * @return array An array of Twig_TokenParserInterface or Twig_TokenParserBrokerInterface instances
   */
  public function getTokenParsers()
  {
    return [];
  }

  /**
   * Returns the node visitor instances to add to the existing list.
   *
   * @return Twig_NodeVisitorInterface[] An array of Twig_NodeVisitorInterface instances
   */
  public function getNodeVisitors()
  {
    return [];
  }

  /**
   * Returns a list of filters to add to the existing list.
   *
   * @return array An array of filters
   */
  public function getFilters()
  {
    return [];
  }

  /**
   * Returns a list of tests to add to the existing list.
   *
   * @return array An array of tests
   */
  public function getTests()
  {
    return [];
  }

  /**
   * Returns a list of functions to add to the existing list.
   *
   * @return array An array of functions
   */
  public function getFunctions()
  {
    return [];
  }

  /**
   * Returns a list of operators to add to the existing list.
   *
   * @return array An array of operators
   */
  public function getOperators()
  {
    return [];
  }

  /**
   * Returns a list of global variables to add to the existing list.
   *
   * @return array An array of global variables
   */
  public function getGlobals()
  {
    return [];
  }
}
