transformers-0.4.3.0: Concrete functor and monad transformers

Copyright(c) 2007 Magnus Therning
LicenseBSD-style (see the file LICENSE)
MaintainerR.Paterson@city.ac.uk
Stabilityexperimental
Portabilityportable
Safe HaskellSafe
LanguageHaskell98

Control.Monad.Trans.Identity

Contents

Description

The identity monad transformer.

This is useful for functions parameterized by a monad transformer.

Synopsis

The identity monad transformer

newtype IdentityT f a Source

The trivial monad transformer, which maps a monad to an equivalent monad.

Constructors

IdentityT 

Fields

runIdentityT :: f a
 

mapIdentityT :: (m a -> n b) -> IdentityT m a -> IdentityT n b Source

Lift a unary operation to the new monad.

Lifting other operations

liftCatch :: Catch e m a -> Catch e (IdentityT m) a Source

Lift a catchE operation to the new monad.

liftCallCC :: CallCC m a b -> CallCC (IdentityT m) a b Source

Lift a callCC operation to the new monad.