Safe Haskell	Safe-Inferred

Util.Logger

Description

A monad like WriterT, but intended for logging.

WriterT is not actually all that good for logging because its (>>=) is not tail recursive.

TODO there's now a CPS version on hackage: writer-cps-mtl It might be more efficient.

Synopsis

data LoggerT w m a
type Logger w a = LoggerT w Identity a
run :: Monad m => LoggerT w m a -> m (a, [w])
runId :: Logger w a -> (a, [w])
exec :: Monad m => LoggerT w m a -> m [w]
class Monad m => MonadLogger w m | m -> w where
- log :: w -> m ()
- peek :: m [w]
logs :: MonadLogger w m => [w] -> m ()
mapLogs :: (w -> w) -> Logger w a -> Logger w a

Documentation

data LoggerT w m a Source #

This uses a plain list for now. DList is not actually very efficient for appends because appending nil doesn't strictly eliminate the nil.

Instances

Instances details

Monad m => MonadLogger w (LoggerT w m) Source #
Instance details Defined in Util.Logger Methods log :: w -> LoggerT w m () Source # peek :: LoggerT w m [w] Source #
MonadError e m => MonadError e (LoggerT w m) Source #
Instance details Defined in Util.Logger Methods throwError :: e -> LoggerT w m a # catchError :: LoggerT w m a -> (e -> LoggerT w m a) -> LoggerT w m a #
MonadReader r m => MonadReader r (LoggerT w m) Source #
Instance details Defined in Util.Logger Methods ask :: LoggerT w m r # local :: (r -> r) -> LoggerT w m a -> LoggerT w m a # reader :: (r -> a) -> LoggerT w m a #
MonadState s m => MonadState s (LoggerT w m) Source #	I think I can't automatically derive this because LoggerT itself is a StateT.
Instance details Defined in Util.Logger Methods get :: LoggerT w m s # put :: s -> LoggerT w m () # state :: (s -> (a, s)) -> LoggerT w m a #
MonadTrans (LoggerT w) Source #
Instance details Defined in Util.Logger Methods lift :: Monad m => m a -> LoggerT w m a #
MonadIO m => MonadIO (LoggerT w m) Source #
Instance details Defined in Util.Logger Methods liftIO :: IO a -> LoggerT w m a #
Monad m => Applicative (LoggerT w m) Source #
Instance details Defined in Util.Logger Methods pure :: a -> LoggerT w m a # (<>) :: LoggerT w m (a -> b) -> LoggerT w m a -> LoggerT w m b # liftA2 :: (a -> b -> c) -> LoggerT w m a -> LoggerT w m b -> LoggerT w m c # (>) :: LoggerT w m a -> LoggerT w m b -> LoggerT w m b # (<*) :: LoggerT w m a -> LoggerT w m b -> LoggerT w m a #
Functor m => Functor (LoggerT w m) Source #
Instance details Defined in Util.Logger Methods fmap :: (a -> b) -> LoggerT w m a -> LoggerT w m b # (<$) :: a -> LoggerT w m b -> LoggerT w m a #
Monad m => Monad (LoggerT w m) Source #
Instance details Defined in Util.Logger Methods (>>=) :: LoggerT w m a -> (a -> LoggerT w m b) -> LoggerT w m b # (>>) :: LoggerT w m a -> LoggerT w m b -> LoggerT w m b # return :: a -> LoggerT w m a #

type Logger w a = LoggerT w Identity a Source #

run :: Monad m => LoggerT w m a -> m (a, [w]) Source #

runId :: Logger w a -> (a, [w]) Source #

exec :: Monad m => LoggerT w m a -> m [w] Source #

class Monad m => MonadLogger w m | m -> w where Source #

Methods

log :: w -> m () Source #

peek :: m [w] Source #

Instances

Instances details

(Monoid w, MonadLogger log m) => MonadLogger log (WriterT w m) Source #
Instance details Defined in Util.Logger Methods log :: log -> WriterT w m () Source # peek :: WriterT w m [log] Source #
Monad m => MonadLogger w (LoggerT w m) Source #
Instance details Defined in Util.Logger Methods log :: w -> LoggerT w m () Source # peek :: LoggerT w m [w] Source #
(Error e, MonadLogger w m) => MonadLogger w (Error.ErrorT e m) Source #
Instance details Defined in Util.Logger Methods log :: w -> Error.ErrorT e m () Source # peek :: Error.ErrorT e m [w] Source #
MonadLogger w m => MonadLogger w (Except.ExceptT e m) Source #
Instance details Defined in Util.Logger Methods log :: w -> Except.ExceptT e m () Source # peek :: Except.ExceptT e m [w] Source #
MonadLogger w m => MonadLogger w (Reader.ReaderT r m) Source #
Instance details Defined in Util.Logger Methods log :: w -> Reader.ReaderT r m () Source # peek :: Reader.ReaderT r m [w] Source #
MonadLogger w m => MonadLogger w (Lazy.StateT s m) Source #
Instance details Defined in Util.Logger Methods log :: w -> Lazy.StateT s m () Source # peek :: Lazy.StateT s m [w] Source #
MonadLogger w m => MonadLogger w (Strict.StateT s m) Source #
Instance details Defined in Util.Logger Methods log :: w -> Strict.StateT s m () Source # peek :: Strict.StateT s m [w] Source #

logs :: MonadLogger w m => [w] -> m () Source #

mapLogs :: (w -> w) -> Logger w a -> Logger w a Source #