Portability | non-portable (multi-param classes, functional dependencies) |
---|---|
Stability | experimental |
Maintainer | libraries@haskell.org |
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
(Monoid w, Monad m, MonadTrans t, Monad (t (WriterT w m)), Monad (t (StateT w m))) => MonadWriter w (t (WriterT w m)) | |
(Monoid w, MonadTrans t, Monad (t (Writer w)), Monad (t (State w))) => MonadWriter w (t (Writer w)) | |
Monoid w => MonadWriter w (Writer w) | |
(Monoid w, Monad m, MonadTrans t, Monad (t (WriterT w m)), Monad (t (StateT w m))) => MonadWriter w (t (WriterT w m)) | |
(Monoid w, MonadTrans t, Monad (t (Writer w)), Monad (t (State w))) => MonadWriter w (t (Writer w)) | |
Monoid w => MonadWriter w (Writer w) | |
(Monoid w, Monad m) => MonadWriter w (WriterT w m) | |
(Monoid w, Monad m) => MonadWriter w (WriterT w m) |
listens :: MonadWriter w m => (w -> b) -> m a -> m (a, b)Source
censor :: MonadWriter w m => (w -> w) -> m a -> m aSource