Modulelog-base-0.12.0.1Haskell2010

Log.Monad

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

4 types
4 values

Packagelog-base-0.12.0.1
Exports8
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-0.12.0.1 · Log.Internal.Logger
Monoid LoggerDefined in log-base-0.12.0.1 · Log.Internal.Logger
Composition of Logger objects.

datadata LoggerEnv

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

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-0.12.0.1 · Log.Monad
MonadTransControl LogTDefined in log-base-0.12.0.1 · Log.Monad
MFunctor LogTDefined in log-base-0.12.0.1 · Log.Monad
```
hoist = mapLogT
```
MonadError e m => MonadError e (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadReader r m => MonadReader r (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadState s m => MonadState s (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadWriter w m => MonadWriter w (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadBase b m => MonadBase b (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadBaseControl b m => MonadBaseControl b (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
Monad m => Monad (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
Functor m => Functor (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadFail m => MonadFail (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
Applicative m => Applicative (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
Alternative m => Alternative (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadPlus m => MonadPlus (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadIO m => MonadIO (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadCatch m => MonadCatch (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadMask m => MonadMask (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadThrow m => MonadThrow (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadUnliftIO m => MonadUnliftIO (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
MonadBase IO m => MonadLog (LogT m)Defined in log-base-0.12.0.1 · Log.Monad
type StM (LogT m) a = ComposeSt LogT m aDefined in log-base-0.12.0.1 · Log.Monad
type StT LogT m = StT InnerLogT mDefined in log-base-0.12.0.1 · 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

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.

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

Transform the computation inside a LogT.

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

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 ())

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.