grabAcidState :: AcidState as -> IO as

basically I just want to return my data from database abstractly or based on a class. 

The reason for this is because I want to have a class instance of state and then I can implement my library like so:

data MyCoolData :: MyCoolData T.Text

class HasCoolData a where

     getCoolDataList :: a -> MyCoolData

grabStoredList :: HasCoolData as => AcidState as -> IO [MyCoolData]

grabStoredList as = do

    cs <- grabAcidState as

    return $ getCoolDataList cs 

and users could implement it like so:

data AppState = AppState {

    someCoolData :: [MyCoolData]

}

instance HasCoolData AppState {

    getCoolDataList = someCoolData

}

However trying to implement this simple behavior has been proving quite difficult. Maybe I am making this too difficult and I should just have a seperate AcidState datatype for my library.

Any help would be appreciated.