monad-journal-0.5: Pure logger typeclass and monad transformer

Portabilityportable
Stabilitystable
Maintainerdimitri.sabadie@gmail.com
Safe HaskellNone

Control.Monad.Trans.Journal

Contents

Description

Monad transformer version of MonadJournal. JournalT provides journaling over a monad.

This modules defines a few useful instances. Check the list below for further information.

Synopsis

JournalT monad transformer

data JournalT w m a Source

Transformer version of MonadJournal.

Instances

MonadBase b m => MonadBase b (JournalT w m) 
(Monoid w, MonadBaseControl b m) => MonadBaseControl b (JournalT w m) 
MonadError e m => MonadError e (JournalT w m) 
MonadReader r m => MonadReader r (JournalT w m) 
MonadState s m => MonadState s (JournalT w m) 
MonadWriter w' m => MonadWriter w' (JournalT w m) 
(Monoid w, Monad m) => MonadJournal w (JournalT w m) 
MonadTrans (JournalT w) 
Monoid w => MonadTransControl (JournalT w) 
Monad m => Monad (JournalT w m) 
Functor m => Functor (JournalT w m) 
MonadPlus m => MonadPlus (JournalT w m) 
(Monad m, Functor m) => Applicative (JournalT w m) 
(Functor m, MonadPlus m) => Alternative (JournalT w m) 
MonadIO m => MonadIO (JournalT w m) 

runJournalT :: (Monoid w, Monad m) => JournalT w m a -> m (a, w)Source

Retrieve the value and the log history.

evalJournalT :: (Monoid w, Monad m) => JournalT w m a -> m aSource

Only retrieve the value.

execJournalT :: (Monoid w, Monad m) => JournalT w m a -> m wSource

Only retrieve the log history.

Re-exported