Online PHP editor | output for IfMW6

<?php function rSplitReverse($string) { preg_match_all("/$((?:(?>[^()]+)|(?R))*)$/", $string, $matches); foreach ($matches[1] as &$m) { if (preg_match_all("/($(?:(?>[^()]+)|(?R))*$)|[^(),]+/", $m, $items, PREG_SET_ORDER)) { $first = array_shift($items)[0]; foreach ($items as &$item) { $item = isset($item[1]) ? rSplitReverse($item[0]) : $item[0]; } $m = "$first," . implode(',', array_reverse($items)); } } return '(' . implode('),(', array_reverse($matches[1])) . ')'; } echo rSplitReverse('(X,1,1,3),(X,1,1,3),(X,@2,@2,@2,@2,@2,(Y,1))');