| Portability | non-portable (multi-param classes, functional dependencies) |
|---|---|
| Stability | experimental |
| Maintainer | libraries@haskell.org |
Control.Monad.Writer.Class
Description
The MonadWriter class.
Inspired by the paper /Functional Programming with Overloading and Higher-Order Polymorphism/, Mark P Jones (http://web.cecs.pdx.edu/~mpj/pubs/springschool.html) Advanced School of Functional Programming, 1995.
Documentation
class (Monoid w, Monad m) => MonadWriter w m | m -> w whereSource
Instances
| Monoid w => MonadWriter w (Writer w) | |
| Monoid w => MonadWriter w (Writer w) | |
| MonadWriter w m => MonadWriter w (ReaderT r m) | |
| (Error e, MonadWriter w m) => MonadWriter w (ErrorT e m) | |
| MonadWriter w m => MonadWriter w (StateT s m) | |
| MonadWriter w m => MonadWriter w (StateT s m) | |
| (Monoid w, Monad m) => MonadWriter w (WriterT w m) | |
| (Monoid w, Monad m) => MonadWriter w (WriterT w m) | |
| Monoid w => MonadWriter w (RWS r w s) | |
| Monoid w => MonadWriter w (RWS r w s) | |
| (Monoid w, Monad m) => MonadWriter w (RWST r w s m) | |
| (Monoid w, Monad m) => MonadWriter w (RWST r w s m) |
listens :: MonadWriter w m => (w -> b) -> m a -> m (a, b)Source
censor :: MonadWriter w m => (w -> w) -> m a -> m aSource