Modulelog-base-0.12.1.0Haskell2010

Log.Monad

The LogT monad transformer for adding logging capabilities to any monad.

Synopsis

data Logger
data LoggerEnv
type InnerLogT
newtype LogT
value runLogT
value logExceptions
value mapLogT
value logMessageIO
value getLoggerIO

Packagelog-base-0.12.1.0
Exports9
LanguageHaskell2010
LicenceBSD-3-Clause
SourceMonad.hs

datadata Logger

An object used for communication with a logger thread that outputs LogMessages using e.g. PostgreSQL, Elasticsearch or stdout (depending on the back-end chosen).

Instances2Semigroup, Monoid

Semigroup LoggerDefined in log-base-0.12.1.0 · Log.Internal.Logger
Monoid LoggerDefined in log-base-0.12.1.0 · Log.Internal.Logger
Composition of Logger objects.

datadata LoggerEnv

Source#

The state that every LogT carries around.

Constructors

LoggerEnv
- leLogger :: !Logger
  The Logger to use.
- leComponent :: !Text
  Current application component.
- leDomain :: ![Text]
  Current application domain.
- leData :: ![Pair]
  Additional data to be merged with the log message's data.
- leMaxLogLevel :: LogLevel
  The maximum log level allowed to be logged.

typetype InnerLogT = ReaderT LoggerEnv

newtypenewtype LogT (m :: Type -> Type) a

Source#

Monad transformer that adds logging capabilities to the underlying monad.

Constructors

LogT
- unLogT :: InnerLogT m a

Instances23MonadTrans, MonadTransControl, MFunctor, MonadError, MonadReader, MonadState, …

MonadTrans LogTDefined in log-base-0.12.1.0 · Log.Monad
MonadTransControl LogTDefined in log-base-0.12.1.0 · Log.Monad
MFunctor LogTDefined in log-base-0.12.1.0 · Log.Monad
```
hoist = mapLogT
```
MonadError e m => MonadError e (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadReader r m => MonadReader r (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadState s m => MonadState s (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadWriter w m => MonadWriter w (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadBase b m => MonadBase b (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadBaseControl b m => MonadBaseControl b (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
Monad m => Monad (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
Functor m => Functor (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadFail m => MonadFail (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
Applicative m => Applicative (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
Alternative m => Alternative (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadPlus m => MonadPlus (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadIO m => MonadIO (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadCatch m => MonadCatch (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadMask m => MonadMask (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadThrow m => MonadThrow (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadUnliftIO m => MonadUnliftIO (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
MonadBase IO m => MonadLog (LogT m)Defined in log-base-0.12.1.0 · Log.Monad
type StM (LogT m) a = ComposeSt LogT m aDefined in log-base-0.12.1.0 · Log.Monad
type StT LogT m = StT InnerLogT mDefined in log-base-0.12.1.0 · Log.Monad

valuerunLogT

:: Text
Application component name to use.
-> Logger
The logging back-end to use.
-> LogLevel
The maximum log level allowed to be logged. Only messages less or equal than this level with be logged.
-> LogT m a
The LogT computation to run.
-> m a

Source#

Run a LogT computation.

Note that in the case of asynchronous/bulk loggers runLogT doesn't guarantee that all messages are actually written to the log once it finishes. Use withPGLogger or withElasticSearchLogger for that.

valuelogExceptions :: (MonadBaseControl IO m, MonadLog m) => m a -> m a

Source#

Ensure uncaught exceptions get logged. Convenient to compose right after runLogT so any exception will show up.

valuemapLogT :: (m a -> n b) -> LogT m a -> LogT n b

Source#

Transform the computation inside a LogT.

valuelogMessageIO :: LoggerEnv -> UTCTime -> LogLevel -> Text -> Value -> IO ()

Source#

Base implementation of logMessage for use with a specific LoggerEnv. Useful for reimplementation of MonadLog instance.

valuegetLoggerIO :: MonadLog m => m (UTCTime -> LogLevel -> Text -> Value -> IO ())

Source#

Return an IO action that logs messages using the current MonadLog context. Useful for interfacing with libraries such as aws or amazonka that accept logging callbacks operating in IO.