/**
* Checks if current position is valid.
*
* @return bool Returns true on success, false otherwise
*/
public function valid()
{
if (is_null($this->current)) {
return true;
}
if ($this->current instanceof RecursiveLeafInterface) {
return $this->current->valid();
}
return false;
}
/**
* Injects leaf in crown of the tree.
*
* @param RecursiveLeafInterface $leaf The leaf
* @param int|string $uniqueKey The unique key of leaf
*/
protected function injectInCrown(RecursiveLeafInterface $leaf, $uniqueKey = null)
{
if (is_null($uniqueKey)) {
$this->crown[] = null;
$uniqueKey = key(array_slice($this->crown, -1, 1, true));
}
$leaf->setUniqueKey($uniqueKey);
$this->crown[$uniqueKey] = $leaf;
}