Copyright | (c) Andy Gill 2001, (c) Oregon Graduate Institute of Science and Technology 2001, (c) Jeff Newbern 2003-2006, (c) Andriy Palamarchuk 2006 |
---|---|

License | BSD-style (see the file LICENSE) |

Maintainer | libraries@haskell.org |

Stability | experimental |

Portability | portable |

Safe Haskell | Safe-Inferred |

Language | Haskell98 |

- Computation type:
- Simple function application.
- Binding strategy:
- The bound function is applied to the input value.
`Identity`

x >>= f ==`Identity`

(f x) - Useful for:
- Monads can be derived from monad transformers applied to the
`Identity`

monad. - Zero and plus:
- None.
- Example type:
`Identity`

a

The `Identity`

monad is a monad that does not embody any computational strategy.
It simply applies the bound function to its input without any modification.
Computationally, there is no reason to use the `Identity`

monad
instead of the much simpler act of simply applying functions to their arguments.
The purpose of the `Identity`

monad is its fundamental role in the theory
of monad transformers.
Any monad transformer applied to the `Identity`

monad yields a non-transformer
version of that monad.