Quick and dirty mixins in Lua

gistfile1.lua

Mixin = {}
Mixin.__index = Mixin
Mixin.__mixins = {Mixin}

function Mixin:__index (method)
  for i=#getmetatable(self).__mixins, 1, -1 do
    local m = getmetatable(self).__mixins[i][method]
    if m then return m end
  end
end

function Mixin:new ()
  return setmetatable({}, Mixin)
end

function Mixin:addmeta (mt)
  table.insert(self.__mixins, mt)
end

function Mixin:removemeta (mt)
  for k, v in pairs(self.__mixins) do
    if v == mt then self.__mixins[k] = nil end
  end
end


-- Usage

obj = Mixin:new()
obj:addmeta(<table>)