id +transformers

module Control.Monad.Trans.Identity
transformers Control.Monad.Trans.Identity
The identity monad transformer. This is useful for functions parameterized by a monad transformer.
module Data.Functor.Identity
transformers Data.Functor.Identity
The identity functor and monad. This trivial type constructor serves two purposes: * It can be used with functions parameterized by functor or monad classes. * It can be used as a base monad to which a series of monad transformers may be applied to construct a composite monad. Most monad transformer modules include the special case of applying the transformer to Identity. For example, State s is an abbreviation for StateT s Identity.
Identity :: a -> Identity a
transformers Data.Functor.Identity
newtype Identity a
transformers Data.Functor.Identity
Identity functor and monad.
IdentityT :: m a -> IdentityT m a
transformers Control.Monad.Trans.Identity
newtype IdentityT m a
transformers Control.Monad.Trans.Identity
The trivial monad transformer, which maps a monad to an equivalent monad.
mapIdentityT :: (m a -> n b) -> IdentityT m a -> IdentityT n b
transformers Control.Monad.Trans.Identity
Lift a unary operation to the new monad.
runIdentity :: Identity a -> a
transformers Data.Functor.Identity
runIdentityT :: IdentityT m a -> m a
transformers Control.Monad.Trans.Identity