Lua inheritance via metatables. Pretty

inheritance.lua

local function __define_class(base)
   local __classmethods = {}  -- define static/classmethods here..

   function __classmethods.new ( cls, ...)  -- classmethod
      local self = setmetatable({}, { __index = cls })
      if self.init then
         self:init(...)
      end
      return self
   end   

   base = base or {}
   local new_subclass = setmetatable(__classmethods, { __index = base })
   return new_subclass
end


local BaseAppClass = __define_class()
function BaseAppClass:init()  
end

local AppClass = __define_class(BaseAppClass)
function AppClass:init(name, css_class)
   BaseAppClass.init(self)
   -- some specifics!
end