
If I have the following type signature transMit :: Serialize a => Socket -> POSIXTime -> KEY -> Maybe a -> TPSQ -> TMap a -> IO () And the function is called with transMit s now key newmsgs q m where newmsgs is whatever type a I get but _not_ a Maybe a then I get the error Could not deduce (a ~ Maybe a) from the context (Serialize a) Can I somehow when I call transmit cast newmsgs into a Maybe newmsgs or so so that the function call fits the type signature? --Joerg

Put a Just around it? transMit s now key (Just newmsgs) q m On Sat 27 Jul 2013 20:05:43 JST, Joerg Fritsch wrote:
If I have the following type signature transMit :: Serialize a => Socket -> POSIXTime -> KEY -> Maybe a -> TPSQ -> TMap a -> IO ()
And the function is called with transMit s now key newmsgs q m where newmsgs is whatever type a I get but _not_ a Maybe a
then I get the error Could not deduce (a ~ Maybe a) from the context (Serialize a)
Can I somehow when I call transmit cast newmsgs into a Maybe newmsgs or so so that the function call fits the type signature?
--Joerg
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Joerg Fritsch
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Niklas Hambüchen