Copyright | (c) Andy Gill 2001, (c) Oregon Graduate Institute of Science and Technology, 2001 |
---|---|
License | BSD-style (see the file libraries/base/LICENSE) |
Maintainer | libraries@haskell.org |
Stability | experimental |
Portability | non-portable (multi-param classes, functional dependencies) |
Safe Haskell | Safe-Inferred |
Language | Haskell98 |
Lazy writer monads.
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
module Control.Monad.Writer.Class
execWriter :: Writer w a -> w Source
WriterT | |
|
(Monoid w, Monad m) => MonadWriter w (WriterT w m) | |
(Monoid w, MonadError e m) => MonadError e (WriterT w m) | |
(Monoid w, MonadState s m) => MonadState s (WriterT w m) | |
(Monoid w, MonadReader r m) => MonadReader r (WriterT w m) | |
Monoid w => MonadTrans (WriterT w) | |
(Monoid w, Monad m) => Monad (WriterT w m) | |
Monad m => Functor (WriterT w m) | |
(Monoid w, MonadPlus m) => MonadPlus (WriterT w m) | |
(Monoid w, MonadIO m) => MonadIO (WriterT w m) | |
(Monoid w, MonadCont m) => MonadCont (WriterT w m) |
execWriterT :: Monad m => WriterT w m a -> m w Source
mapWriterT :: (m (a, w) -> n (b, w')) -> WriterT w m a -> WriterT w' n b Source
module Control.Monad
module Control.Monad.Trans
module Data.Monoid