[Haskell-cafe] Bug in HLint or haskell-src-exts?

Martin Huschenbett huschi at gmx.org
Thu Feb 26 16:44:57 EST 2009

Hello Haskellers,

I've got the following piece of code

type Memory addr value = Map.Map addr value

type Stack item = [item]

data MachineState addr value item = MachineState
   { memory :: Memory addr value
   , stack  :: Stack item
   deriving (Show)

newtype Machine addr value item m a =
     Machine { unMachine :: StateT (MachineState addr value item) m a }
   deriving (Monad, MonadState (MachineState addr value item), 
MonadTrans, MonadIO)

and HLint complains:

Machine.hs:20:31: Parse failure, Parse error

This is exactly the position of the opening bracket after MonadState. 
Why can GHC parse this and HLint cannot?



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