| Copyright | (c) Andy Gill 2001, (c) Oregon Graduate Institute of Science and Technology 2001 |
|---|---|
| License | BSD-style (see the file LICENSE) |
| Maintainer | ross@soi.city.ac.uk |
| Stability | experimental |
| Portability | portable |
| Safe Haskell | Trustworthy |
| Language | Haskell2010 |
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 sis an abbreviation forStateT s.Identity
Since: 4.8.0.0
- newtype Identity a = Identity {
- runIdentity :: a
Documentation
Identity functor and monad. (a non-strict monad)
Since: 4.8.0.0
Constructors
| Identity | |
Fields
| |
Instances
| Monad Identity | |
| Functor Identity | |
| MonadFix Identity | |
| Applicative Identity | |
| Foldable Identity | |
| Traversable Identity | |
| Eq a => Eq (Identity a) | |
| Ord a => Ord (Identity a) | |
| Read a => Read (Identity a) | This instance would be equivalent to the derived instances of the
|
| Show a => Show (Identity a) | This instance would be equivalent to the derived instances of the
|
| Typeable (* -> *) Identity | |
| Typeable (a -> Identity a) (Identity a) |