# The compose-trans package

A version of monad transformers that (a) allows one to convince the type checker that transformer application is a monad, and (b) doesn't need lots of boilerplate to add a new transformer. It's supposed to play nicely with `Control.Monad.Trans`

.

In order to make a new transformer (say, `T`

) an instance of `TransM`

(`TransP`

, `TransF`

) class, all you have to do is:

define

`instance MonadTrans T`

— which you've probably done alreadydefine

`instance Monad m => Monad (T m)`

— also something quite common (for`TransP`

and`TransF`

you'd need another instance for`MonadPlus`

and`MonadFix`

, respectively).write

`instance Trans T where transMInst = instM`

— which is exactly one line of boilerplate. Sorry about that.

After that, you can use your new and shiny transformer in compositions, like `ReaderT Char :. T :. WriterT String`

— and such a composition would automagically become a monad transformer.

## Properties

Versions | 0.0, 0.1 |
---|---|

Dependencies | base (>=2 && <5), mtl [details] |

License | BSD3 |

Author | Miguel Mitrofanov |

Maintainer | miguelimo38@yandex.ru |

Category | Monads |

Uploaded | Sat Nov 5 13:10:11 UTC 2011 by MiguelMitrofanov |

Distributions | NixOS:0.1 |

Downloads | 634 total (12 in the last 30 days) |

Rating | (no votes yet) [estimated by rule of succession] |

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Status | Docs uploaded by user Build status unknown [no reports yet] Hackage Matrix CI |

## Downloads

- compose-trans-0.1.tar.gz [browse] (Cabal source package)
- Package description (included in the package)