Safe Haskell	Safe
Language	Haskell2010

Control.Monad.Logger

Description

A replacement for WriterT IO which uses mutable references.

Synopsis

newtype Logger w a = Logger {
- runLogger :: IORef w -> IO a
}
runLogger' :: Monoid w => Logger w a -> IO (a, w)

Documentation

newtype Logger w a Source #

A replacement for WriterT IO which uses mutable references.

Constructors

Logger
Fields runLogger :: IORef w -> IO a

Instances

Monoid w => MonadBase IO (Logger w) Source #
Instance details Defined in Control.Monad.Logger Methods liftBase :: IO α -> Logger w α #
Monoid w => MonadBaseControl IO (Logger w) Source #
Instance details Defined in Control.Monad.Logger Associated Types type StM (Logger w) a :: Type # Methods liftBaseWith :: (RunInBase (Logger w) IO -> IO a) -> Logger w a # restoreM :: StM (Logger w) a -> Logger w a #
Monoid w => MonadWriter w (Logger w) Source #
Instance details Defined in Control.Monad.Logger Methods writer :: (a, w) -> Logger w a # tell :: w -> Logger w () # listen :: Logger w a -> Logger w (a, w) # pass :: Logger w (a, w -> w) -> Logger w a #
Monoid w => Monad (Logger w) Source #
Instance details Defined in Control.Monad.Logger Methods (>>=) :: Logger w a -> (a -> Logger w b) -> Logger w b # (>>) :: Logger w a -> Logger w b -> Logger w b # return :: a -> Logger w a # fail :: String -> Logger w a #
Functor (Logger w) Source #
Instance details Defined in Control.Monad.Logger Methods fmap :: (a -> b) -> Logger w a -> Logger w b # (<$) :: a -> Logger w b -> Logger w a #
Monoid w => Applicative (Logger w) Source #
Instance details Defined in Control.Monad.Logger Methods pure :: a -> Logger w a # (<>) :: Logger w (a -> b) -> Logger w a -> Logger w b # liftA2 :: (a -> b -> c) -> Logger w a -> Logger w b -> Logger w c # (>) :: Logger w a -> Logger w b -> Logger w b # (<*) :: Logger w a -> Logger w b -> Logger w a #
Monoid w => MonadIO (Logger w) Source #
Instance details Defined in Control.Monad.Logger Methods liftIO :: IO a -> Logger w a #
type StM (Logger w) a Source #
Instance details Defined in Control.Monad.Logger type StM (Logger w) a = a

runLogger' :: Monoid w => Logger w a -> IO (a, w) Source #

Run a Logger computation, starting with an empty log.