print join ",", map { &{$field_info{$_}{format}}($deal) } @fields;

It took me some time to figure out what that construct meant and where the actual formatting information was. His argument was that this was a perfectly fine thing to do. He did it all of the time, and it allowed you to separate presentation from content. He admitted that the first time you saw it, it looked a bit strange, but if you knew what it did...

That turned out to be a good lesson for me. This construct really was integral to his style, and once I got past the shock of that line it really was maintainable.