transformers-0.3.0.0: Concrete functor and monad transformers

Portabilityportable
Stabilityexperimental
Maintainerross@soi.city.ac.uk
Safe HaskellSafe-Inferred

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 a Source

Identity functor and monad.

Constructors

Identity 

Fields

runIdentity :: a
 

Instances

Monad Identity 
Functor Identity 
MonadFix Identity 
Applicative Identity 
Foldable Identity 
Traversable Identity