Repository navigation
Prelude.undefined while unpickling #1
Description
Hi, I am running this code on a protocol 2 file:
main :: IO ()
main = do putStrLn "Start"
byteString <- S.readFile worldFileName :: IO S.ByteString
let res = unpickle byteString
case res of
Left err -> putStrLn $ "Can't unpickle .\nUnpickling error:\n " ++ err
Right v -> putStrLn "Well done!"
putStrLn "Done"
And I keep getting:
Start
civs: Prelude.undefined
where civs is the name of my app. Do you know what I am doing wrong?
Activity
noteed commentedon Sep 25, 2014
Probably nothing, I think I didn't implement everything. I will get a look. Could you please give me a minimal test file that triggers the problem ?
(I'm very happy to get this issue; I didn't know someone was using this library !)
noteed commentedon Sep 25, 2014
Indeed there are plenty of
undefinedin the code (i.e. corresponding to non-implemented op-codes). I'm willing to add missing op-codes for "standard" pickle data (i.e. probably no support for user-defined classes and instance, or for things supported bypicklebut not bycPickle).ftomassetti commentedon Sep 29, 2014
Thank you for writing and sharing this library. I am a real beginner in Haskell but I would try to help if I could find the documentation for the pickle protocol
noteed commentedon Sep 29, 2014
Have a look at the README, I think there is some pointer to learn the Pickle format. That being said if you can give me a sample file that you're trying to parse (possible the smallest example that triggers the
undefined), I would look into fixing the problem.ftomassetti commentedon Sep 29, 2014
The file is quite large, but looking at it with pickle tools these are the opcodes used at the beginning:
After that we have thousands of BINGET, BINFLOAT, BININT1
The end of the file looks like:
noteed commentedon Sep 29, 2014
Thanks! That's a good start. Looking at the source,
GLOBALis not implemented in the parser, andGLOBAL,NEWOBJandBUILDare not implemented in the stack machine.Unfortunately we're in the realm of Python classes and objects:
can be understood as
geo.World(), i.e. instanciation of ageo.Worldclass. This is clearly outside the scope of this library. Then a big dictionary is constructed (everything starting atEMPTY_DICT). That is perfectly ok for this library. ThenBUILDis called to update thegeo.World()instance's__dict__with the constructed dictionary. Again something that is out of scope for this library.Now we could decide that having a minimal representation (and not a full blown representation of Python classes and objects) for that case is doable, e.g. augment the
Valuedata type to haveI think I'm ok with such an option.
The good news is I think you have a perfectly good workaround: remove that part
and also
and you should be able to parse that file and obtain a dictionary.
EDIT: actually
BINGETmust be first implemented but it seems straightforward. I will see to do it.noteed commentedon Sep 29, 2014
I have implented
BINGETin commit 8f403de.