transformers-0.3.0.0: Concrete functor and monad transformers

Copyright(c) Andy Gill 2001, (c) Oregon Graduate Institute of Science and Technology 2001
LicenseBSD-style (see the file LICENSE)
Maintainerross@soi.city.ac.uk
Stabilityexperimental
Portabilityportable
Safe HaskellSafe-Inferred
LanguageHaskell98

Data.Functor.Identity

Description

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.

Synopsis

Documentation

newtype Identity aSource

Identity functor and monad.

Constructors

Identity 

Fields

runIdentity :: a