I've been using JS on and off in various incarnations, and this sort of blows my mind. First because I don't think I've ever seen that approach used anywhere, a

I've been using JS on and off in various incarnations, and this sort of blows my mind. First because I don't think I've ever seen that approach used anywhere, and second because it would probably take me upwards of an hour (possibly a day) to work out whether that would actually work.