Safe Haskell | None |
---|---|

Language | Haskell2010 |

- data WriterT s m a
- runWriterT :: Monoid s => WriterT s m a -> m (a, s)
- pattern WriterT :: forall m s a. (Functor m, Monoid s) => m (a, s) -> WriterT s m a
- type Writer s = WriterT s Identity
- runWriter :: Monoid s => Writer s a -> (a, s)
- pattern Writer :: forall s a. Monoid s => (a, s) -> Writer s a
- execWriterT :: (Monad m, Monoid s) => WriterT s m a -> m s
- evalWriterT :: (Monad m, Monoid s) => WriterT s m a -> m a
- execWriter :: Monoid s => Writer s a -> s
- evalWriter :: Monoid s => Writer s a -> a

# Documentation

A monad transformer similar to `WriterT`

, except
that it does not leak space.

runWriterT :: Monoid s => WriterT s m a -> m (a, s) Source #

execWriter :: Monoid s => Writer s a -> s Source #

evalWriter :: Monoid s => Writer s a -> a Source #