>> If I'm running register outside runWriterT everything will work.

Maybe just

> lift $ register $ print "freed2"

or I didn't catch something?



2012/3/1 Alexander V Vershilov <alexander.vershilov@gmail.com>
Hello.

I'm trying to add monad stack into network-conduit, and everything
works except some details [1].

I've run runReaderT $ runTCPServer (wrapper around runResourceT) and
inside conduit I want to run writer to gather results of inner computation.
In inner computation I want to use IO, data from outter stack (ReaderT)
so I'm running {-1-}:

 (k,t) <- lift $ runWriterT $ ask >>= \x -> tell [x]     {- 1 -}

and {-2-}

 (k,t) <- lift $ runWriterT $ do {- 2 -}
                   x <- ask
                   liftIO $ print $x+1
                   tell [x]

and that will work (except I've thought I should not lift runWriterT, but
calling functions inside.

And finally in computation that will run once I want to register cleaning
function (for example register $ putStrLn "cleaned") ({-3-})

 (k,t) <- lift $ runWriterT $ do {- 3 -}
                   x <- ask
                   liftIO $ print $x+1
                   register $ print "freed2"
                   tell [x]

but I've got type error. If I'm running register outside runWriterT everything
will work.

I would apperated if there will be any suggestions how to make this code
better or use register in internal computation (runWriterT)

[1] https://gist.github.com/1941151
--
Best regards,
 Alexander V Vershilov

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