I am not sure... I don't think it does.Roland_Yonaba wrote: Actually it already does thanks to the metatable's __index metamethod
Or am I missing something ?Code: Select all
function Proxy(f) return setmetatable({}, {__index = function(self, k) local v = f(k) self[k] = v return v end}) end
Anickyan wrote:I am not sure... I don't think it does.
Code: Select all
t = setmetatable({}, {__index = function(self,k)
print(('Key %s missing! So __index will create a new one!'):format(k))
self[k] = true
return self[k]
end})
print('Call 1', t.z)
--> Key z missing! So __index will create a new one!
--> Call 1 true
print('Call 2', t.z)
--> Call 2 true
print('Call 3', t.z)
--> Call 3 true
Code: Select all
t = setmetatable({}, {__index = function(self,k)
print(('Key %s missing! So __index will create a new one!'):format(k))
-- note we do not change self
return true
end})
print('Call 1', t.z)
--> Key z missing! So __index will create a new one!
--> Call 1 true
print('Call 2', t.z)
--> Key z missing! So __index will create a new one!
--> Call 2 true
print('Call 3', t.z)
--> Key z missing! So __index will create a new one!
--> Call 3 true