On Fri, Mar 21, 2008 at 11:02 AM, Paul Johnson
This effectively duplicates the AmqpVariant solution. It would work, but it feels horrible. I get the feeling that there ought to be a better way, possibly using classes or existential types. Any suggestions?
Firstly, I would use the Get and Put monads directly, rather than making them instances of Binary. I think, if I were doing it, I would start off with something like this: class AMQPValue a where putAMQP :: a -> Put instance AMQPValue Word8 where putAMQP v = putWord8 1 >> putWord8 v ... (many instances) instance (AMQPValue a) => AMQPValue [a] where putAMQP vs = putWord8 (length vs) >> mapM_ putAMQP vs You probably want a getAMQP member of the AMQPValue class too. Also
getter <- fmap (amqpGetTable !) getWord8 getter
is just
fmap (amqpGetTable !) getWord8
Hope that helps some AGL -- Adam Langley agl@imperialviolet.org http://www.imperialviolet.org