Class definition in Lua

Class.lua

-------------------- Base Class --------------------

local Base = {}


---- Member Methods ----
function Base:foo()
  return 'foo.'
end

function Base:say()
  io.write(self.name..' : '..self.foo())
  io.write('\n')
end

-- Constructor
function Base:init()
  self.name = 'Luatan'
end


---- Class Method ----
Base.new = function()
  local obj = setmetatable({},{__index=Base})
  obj:init()
  return obj
end



-------------------- Inherited Class --------------------
--
local Inherited = setmetatable({}, {__index=Base})


---- Member Methods ----

-- override the method
function Inherited:foo()
  return '(^q^)'
end

-- Constructor
function Inherited:init()
  -- Calling constructor of parent class
  Base.init(self)
end



---- Class Method ----
Inherited.new = function()
  local obj = setmetatable({},{__index=Inherited})
  obj:init()
  return obj
end

----------------------------------------------------


local obj0 = Base.new()
local obj1 = Inherited.new()

obj0:say()
obj1:say()