code: private function nest($x, $node, $end = false)
  	{
  		array_push($x->stmtStack, $node);
  		$n = $this->statement($x);
  		array_pop($x->stmtStack);
  
  		if ($end)
  			$this->t->mustMatch($end);
  
  		return $n;
  	}
docs: Statement stack and nested statement handler.