System.Logger.Logger.Internal

This module provides a logger that implements the logger interface that is defined in System.Logger.Types.

If you want to roll your own implementation you may use the code in this module as an example and starting point.

Logger Configuration

data LoggerConfig

Logger Configuration

Constructors

LoggerConfig

Fields

_loggerConfigQueueSize :: !Int

_loggerConfigThreshold :: !LogLevel

initial log threshold, can be changed later on

_loggerConfigScope :: !LogScope

initial stack of log labels, can be extended later on

_loggerConfigPolicy :: !LogPolicy

how to deal with a congested logging pipeline

Instances

Eq LoggerConfig

Ord LoggerConfig

Read LoggerConfig

Show LoggerConfig

Generic LoggerConfig

ToJSON LoggerConfig

NFData LoggerConfig

Typeable * LoggerConfig

FromJSON (LoggerConfig -> LoggerConfig)

type Rep LoggerConfig

loggerConfigQueueSize :: Lens' LoggerConfig Int

loggerConfigThreshold :: Lens' LoggerConfig LogLevel

loggerConfigScope :: Lens' LoggerConfig LogScope

defaultLoggerConfig :: LoggerConfig

validateLoggerConfig :: ConfigValidation LoggerConfig λ

pLoggerConfig :: MParser LoggerConfig

Logger

data Logger a

Instances

Generic (Logger a)

LoggerCtx (Logger a) a

Typeable (* -> *) Logger

type Rep (Logger a)

loggerScope :: Lens' (Logger a) LogScope

loggerThreshold :: Lens' (Logger a) LogLevel

createLogger :: MonadIO μ => LoggerConfig -> LoggerBackend a -> μ (Logger a)

releaseLogger :: MonadIO μ => Logger a -> μ ()

withLogger :: (MonadIO μ, MonadBaseControl IO μ) => LoggerConfig -> LoggerBackend a -> (Logger a -> μ α) -> μ α

Provide a computation with a Logger.

Here is an example how this can be used to run a computation with a MonadLog constraint:

withConsoleLogger
    ∷ (MonadIO m, MonadBaseControl IO m)
    ⇒ LogLevel
    → (LoggerT T.Text m α)
    → m α
withConsoleLogger level = do
    backend ← mkHandleLoggerBackend $ config ^. loggerConfigBackend
    withLogger config backend ∘ flip runLoggerT
  where
    config = defaultLoggerConfig
        & loggerConfigThreshold .~ level

loggCtx :: (Show a, Typeable a, NFData a) => Logger a -> LogFunctionIO a

withLogFunction :: (Show a, Typeable a, NFData a, MonadIO μ, MonadBaseControl IO μ) => LoggerConfig -> LoggerBackend a -> (LogFunctionIO a -> μ α) -> μ α

For simple cases, when the logger threshold and the logger scope is constant this function can be used to directly initialize a log function.

LoggerT Monad Transformer

type LoggerT a = LoggerCtxT (Logger a)

runLoggerT :: LoggerT a m α -> Logger a -> m α

runLogT :: (MonadBaseControl IO m, MonadIO m) => LoggerConfig -> LoggerBackend msg -> LoggerT msg m α -> m α

Convenience function that unwraps a MonadLog computation over a newly created Logger