Control.Monad.IO.Class
Control.Monad.Trans.Class
Control.Monad.Trans.Cont
Control.Monad.Trans.Except
Control.Monad.Trans.Maybe
Control.Monad.Trans.Reader
Control.Monad.Trans.State
Control.Monad.Trans.Writer
A portable library of functor and monad transformers from https://hackage.haskell.org/package/transformers , originally inspired by the paper
This package contains:
the monad transformer class (in Control.Monad.Trans.Class)
concrete functor and monad transformers, each with associated operations and functions to lift operations associated with other transformers.