Module Control.Monad.Trans.Writer

Summary of exported operations:

writer
                  :: Monad a => (b,c) -> WriterT c a b

tell
                  :: Monad a => b -> WriterT b a ()

listen
                  :: Monad a => WriterT b a c -> WriterT b a (c,b)

execWriterT
                  :: Monad a => WriterT b a c -> a b

mapWriterT
                  ::  (a (b,c) -> d (e,f)) -> WriterT c a b -> WriterT f d e

runWriter
                  ::  WriterT a Identity b -> (b,a)

execWriter
                  ::  WriterT a Identity b -> a

newtype WriterT

Constructor:

Writer

Type synonym: Writer a = WriterT a Identity

writer :: Monad a => (b,c) -> WriterT c a b

tell :: Monad a => b -> WriterT b a ()

listen :: Monad a => WriterT b a c -> WriterT b a (c,b)

execWriterT :: Monad a => WriterT b a c -> a b

mapWriterT :: (a (b,c) -> d (e,f)) -> WriterT c a b -> WriterT f d e