* * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */ namespace Symfony\Bridge\Twig\NodeVisitor; /** * @author Jean-François Simon */ class Scope { /** * @var Scope|null */ private $parent; /** * @var Scope[] */ private $children; /** * @var array */ private $data = array(); /** * @var boolean */ private $left = false; /** * @param Scope $parent */ public function __construct(Scope $parent = null) { $this->parent = $parent; } /** * Opens a new child scope. * * @return Scope */ public function enter() { $child = new self($this); $this->children[] = $child; return $child; } /** * Closes current scope and returns parent one. * * @return Scope|null */ public function leave() { $this->left = true; return $this->parent; } /** * Stores data into current scope. * * @param string $key * @param mixed $value * * @throws \LogicException * * @return Scope Current scope */ public function set($key, $value) { if ($this->left) { throw new \LogicException('Left scope is not mutable.'); } $this->data[$key] = $value; return $this; } /** * Tests if a data is visible from current scope. * * @param string $key * * @return boolean */ public function has($key) { if (array_key_exists($key, $this->data)) { return true; } if (null === $this->parent) { return false; } return $this->parent->has($key); } /** * Returns data visible from current scope. * * @param string $key * @param mixed $default * * @return mixed */ public function get($key, $default = null) { if (array_key_exists($key, $this->data)) { return $this->data[$key]; } if (null === $this->parent) { return $default; } return $this->parent->get($key, $default); } }