/**
* Quotes left and right hand primitive values according to node type
* @param mixed $left_v the lhs value (will be modified)
* @param string $left_nt the lhs node type
* @param mixed $right_v the rhs value (will be modified)
* @param string $right_nt the rhs node type
* @return string|true
*/
protected function qq(&$left_v, $left_nt, &$right_v, $right_nt)
{
// case one: left variable, right value
if ($left_nt == EPQ_N_VARIABLE && $right_nt != EPQ_N_VARIABLE && false === strpos($right_nt, 'EPQ_N_EXPR_')) {
if ($right_nt != EPQ_N_NUMBER) {
return $this->_qq($right_v, $left_v);
} else {
return $this->_qq($dummy = '', $left_v);
}
} else {
if ($left_nt != EPQ_N_VARIABLE && false === strpos($left_nt, 'EPQ_N_EXPR_') && $right_nt == EPQ_N_VARIABLE) {
if ($left_nt != EPQ_N_NUMBER) {
return $this->_qq($left_v, $right_v);
} else {
return $this->_qq($dummy = '', $right_v);
}
}
}
// case three: left func, right value
if (false !== strpos($left_nt, 'EPQ_N_FUNC_') && $right_nt != EPQ_N_VARIABLE && false === strpos($right_nt, 'EPQ_N_EXPR_')) {
if ($right_nt != EPQ_N_NUMBER) {
$right_v = $this->pm->quote($right_v);
}
return true;
} else {
if ($right_nt == EPQ_N_EXPR_UNARY && $left_nt == EPQ_N_VARIABLE && ($right_v == 'NULL' || $right_v == 'NOT NULL')) {
return $this->_qq($dummy = '', $left_v);
} else {
if ($right_nt == EPQ_N_VARIABLE && $left_nt == EPQ_N_VARIABLE) {
$this->_qq($dummy = '', $left_v);
$this->_qq($dummy = '', $right_v);
}
}
}
// done for all else
return true;
}
