Give a pseudocode example of how it would behave.

I have a gut feeling you'll get fifty examples of how you can already do it - really well, with little code.

Perl is merciless for already being able to do whatever you're thinking it should be able to do.

Here's an example. If you look at the op, the whole thing is humbling. I thought that ikegami was conjuring magic, but he pointed out it's in perldoc..
Makes you wonder just what the diff between a mediocre dev like myself and a real guru is.. maybe it's that they RTFM.