System.Console.Haskeline.ReaderT

import System.Console.Haskeline qualified as H

runApp :: ReaderT (InputTEnv IO) IO ()
runApp = do
  input <- toReaderT (H.getInputLine "Enter your name: ")
  ...

-- MTL-style polymorphism
class MonadHaskeline m where
  getInputLine :: String -> m (Maybe String)

-- AppT is the core type over ReaderT.
instance MonadHaskeline (AppT m) where
  getInputLine = lift . toReaderT . H.getInputLine

runApp :: (MonadHaskeline m) => m ()
runApp = do
  input <- getInputLine "Enter your name: "
  ...

import System.Console.Haskeline qualified as H

-- Could be generalized to MonadReader, effects libraries.
runApp :: ReaderT (InputTEnv IO) IO ()

main :: IO ()
main = H.runInputT H.defaultSettings $ fromReaderT runApp