一种不用元表的简单对象实现

function createRobot(name, id)
local obj = { name = name, id = id }
function obj:SetName(name)
self.name = name
end
function obj:GetName()
return self.name
end
function obj:GetId()
return self.id
end
return obj
end
function createFootballRobot(name,
id, position)
local obj = createRobot(name, id)
obj.position = "right back"
function obj:SetPosition(p)
self.position = p
end
function obj:GetPosition()
return self.position
end
return obj
end