function caching_inherit(self, ...)
local parent_classes = {...}
local cache = {}
local meta = {__index = function(self, k)
local cached_value = cache[k]
if cached_value ~= nil then
return cached_value
else
for _, parent_object in ipairs(parent_classes) do
local parent_value = parent_object[k]
if parent_value ~= nil then
cache[k] = parent_value
return parent_value
end
end
end
end}
setmetatable(self, meta)
return self
end
A = {a='A.a', b='A.b', c='A.c'}
B = {b='B.b', x='B.x'}
C = {c='C.c'}
X = caching_inherit({x='X.x'}, B, C, A)
print('X.a == ', X.a)
print('X.b == ', X.b)
print('X.c == ', X.c)
print('X.x == ', X.x)