I'm working now on PHP. One thing i really like is OOP in this lang. We have simple classes, objects and also inheritance, interfaces etc. It would be awesome if it would be possible for ex. create PoliceVehicle class which gets all methods and variables from Vehicle class and work like a normal vehicle. It would improve iterations (cause i don't need to do getElementsByType('vehicle') and iterate all vehicle but simple getElementsByType('policevehicle')) and speed up searching. And also it would optimalize code.
One more thing - improve OOP in Lua by adding class() function or some constructor() for constructor etc. It would be really pro and awesome!