Monadoc
The latest version of compose-trans is 0.1-0.

compose-trans

Version 0.0 revision 0 uploaded by MiguelMitrofanov.

Package meta

Synopsis
Composable monad transformers
Description

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 already

  • define 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 for 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 transmormer.

Author
Miguel Mitrofanov
Bug reports
n/a
Category
Monads
Copyright
n/a
Homepage
n/a
Maintainer
miguelimo38@yandex.ru
Package URL
n/a
Stability
n/a

Components