transformers-0.3.0.0: Concrete functor and monad transformers

Copyright(c) 2007 Magnus Therning
LicenseBSD-style (see the file LICENSE)
Maintainerross@soi.city.ac.uk
Stabilityexperimental
Portabilityportable
Safe HaskellSafe-Inferred
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 m a Source

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

Constructors

IdentityT 

Fields

runIdentityT :: m 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 :: (m a -> (e -> m a) -> m a) -> IdentityT m a -> (e -> IdentityT m a) -> IdentityT m a Source

Lift a catchError operation to the new monad.

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

Lift a callCC operation to the new monad.