/**
* Enter description here...
*
* @param OpExpr $left
* @param ExprOp $op
* @param OpExpr $right
* @param boolean $not
*/
public function transform(&$left, &$op, &$right, &$not)
{
if (!$left->isOpExpr() || !$right->isOpExpr() || !DefaultOpCollection::isBoolean($op)) {
return;
}
if ($left->isTextOnly() && $right->isDBonly()) {
// we just swap the items around, to ease other transformations
$tmp = $left;
$left = $right;
$right = $tmp;
return;
}
if ($op != $right->op() || !DefaultOpCollection::isBoolean($right)) {
return;
}
if ($op == ExprOp::OP_OR && ($not || $right->not())) {
// NOTE: we can't transform. e.g.
// db or !(db or txt) => db or !db and !txt
// so nothing to do
// BUT: db and !(db and txt) => db and !db and !txt
return;
}
$rightLeft = $right->left();
$rightRight = $right->right();
if ($left->isDBonly() && $rightLeft->isDBonly()) {
$newLeft = new OpExpr($left, $op, $rightLeft);
$right = $rightRight;
$left = $newLeft;
return;
}
if ($left->isTextOnly() && $rightRight->isTextOnly()) {
$newRight = new OpExpr($left, $op, $rightRight);
$left = $rightLeft;
$right = $newRight;
return;
}
}