ghci> import Control.Exception.Safe
ghci> :i MonadThrow
class Monad m => MonadThrow (m :: * -> *) where
  Control.Monad.Catch.throwM :: Exception e => e -> m a
  {-# MINIMAL throwM #-}
        -- Defined in ‘Control.Monad.Catch’
instance MonadThrow [] -- Defined in ‘Control.Monad.Catch’
instance MonadThrow Maybe -- Defined in ‘Control.Monad.Catch’
instance MonadThrow IO -- Defined in ‘Control.Monad.Catch’
instance e ~ SomeException => MonadThrow (Either e)
  -- Defined in ‘Control.Monad.Catch’
ghci> :i MonadCatch
class MonadThrow m => MonadCatch (m :: * -> *) where
  Control.Monad.Catch.catch :: Exception e =>
                               m a -> (e -> m a) -> m a
  {-# MINIMAL catch #-}
        -- Defined in ‘Control.Monad.Catch’
instance MonadCatch IO -- Defined in ‘Control.Monad.Catch’
instance e ~ SomeException => MonadCatch (Either e)
  -- Defined in ‘Control.Monad.Catch’
ghci>