# indexed-transformers
An [Atkey indexed monad](https://bentnib.org/paramnotions-jfp.pdf)
is an endo`Functor` [enriched category](https://ncatlab.org/nlab/show/enriched+category),
or [efect](https://mail.haskell.org/pipermail/haskell-cafe/2004-July/006448.html) for short.
An indexed monad transformer transforms a `Monad` into an indexed monad.
This library provides
- a typeclass for indexed monad transformers
- qualified do notation to use with them
- a typeclass for free indexed monad transformers
- a typeclass for state indexed monad transformers
- and instances for the
- free indexed monad transformers
- codensity indexed monad transformers
- continuation indexed monad transformer
- state indexed monad transformer
- writer indexed monad transformer