I know it's eons old but I just noticed this (when looking for if there was some easy one-liner for this); it's good that that was removed from that FAQ mentioned above in the first answer.

Since return() casts in list context:

return reverse $input;

will not work (at least not as expected), as it reverses the list of the result, e.g. ('098,765,432,1') to ('098,765,432,1') (it's a list of one).

What you'd need is:

return scalar reverse $input;