noclass2.lua

-- example class Foo
local Foo = {
  attr1 = 1,
  attr2 = 2,
}
Foo.__index = Foo

function Foo:getattr1()
  return self.attr1
end

function Foo:getattr2()
  return self.attr1
end

-- example class Bar which inherits from Foo
local Bar = {
  attr3 = 3,
  attr1 = 4,
}
for k,v in pairs(Foo) do Bar[k] = v end
Bar.__index = Bar

function Bar:getattr3()
  return self.attr3
end


-- usage

inst = setmetatable({attr3=1337}, Bar)
print(inst:getattr3(3))