メモ
<!DOCTYPE html> <title></title> <script> var s = '2 + (( a + b * c) / d ) * ( e - f ) + 1'; var r = /^(.*?)\(([^\(\)]+)?\)(.*?)$/; var k; var cnt = 0; document.write (s, '<br>'); while (k = r.exec (s)) { k[2] = '$' + cnt++; k.shift (); s = k.join (''); document.write (s, '<br>'); } </script>