CSqlLevel::lookBackwardFor

protected function lookBackwardFor($token)
{
	$pos = $this->current - 1;
	while (isset($this->tokens[$pos]))
	{
		if ($this->tokens[$pos][1] == $token)
			return true;
		elseif ($this->tokens[$pos][0] !== T_WHITESPACE)
			return false;
		$pos--;
	}
	return false;
}