Type constraints on a?

[Simon]

Hello!

I have a hard time defining bind correcly without having to globally type constrain a somehow .. in the newtype defintion for example.
Am I completely off designwise? Some hints would be greatly appreciated

Thanks

[Adriaan Leijnse]

I had the same issue; make sure you only use show/read when pattern matching on the result of

io :: (Show a, Read a) => IO a -> Replay q r a