what.lua

local classes = { }

local function class(name)
	return setmetatable({
		extends = function(self, super)
			self.__super = classes[super]
			return self
		end
	}, {
		__call = function(self, def)
			if self.__super then
				getmetatable(self).__index = self.__super
			end
			classes[name] = setmetatable(def, { __index=self })
		end,
	})
end

local function new(name)
	return setmetatable({}, {
		__call = function(self, ...)
			local C = classes[name]
			local inst = setmetatable({}, {__index=C})
			if C.new then
				C.new(inst)
			end
			return inst
		end,
	})
end

class "Foo" {
	x = "asdf",
	getx = function(self)
		return self.x
	end,
}

class "Bar" : extends "Foo" {
	x = "fdsa",
}

class "Baz" : extends "Foo" {
	x = 1234,
}


local foo = new "Foo" ()
local bar = new "Bar" ()
local baz = new "Baz" ()
print(foo:getx(), bar:getx(), baz:getx())