+ case 'join':
+ if (!$arg) {
+ return null;
+ }
+ list($other, $extra) = $this->split_arg($arg);
+ if ($extra) {
+ return null;
+ } else {
+ return new JoinCommand($user, $other);
+ }
+ case 'drop':
+ if (!$arg) {
+ return null;
+ }
+ list($other, $extra) = $this->split_arg($arg);
+ if ($extra) {
+ return null;
+ } else {
+ return new DropCommand($user, $other);
+ }