protected function _getVariable($tag_name) {
		if ($tag_name === '.') {
			return $this->_context[0];
		} else if (strpos($tag_name, '.') !== false) {
			$chunks = explode('.', $tag_name);
			$first = array_shift($chunks);

			$ret = $this->_findVariableInContext($first, $this->_context);
			foreach ($chunks as $next) {
				// Slice off a chunk of context for dot notation traversal.
				$c = array($ret);
				$ret = $this->_findVariableInContext($next, $c);
			}
			return $ret;
		} else {
			return $this->_findVariableInContext($tag_name, $this->_context);
		}
	}