System.Logger.Logger

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

All the code of this module is in System.Logger.Logger.Internal.

The definitions in System.Logger.Types are re-exported by this module.

Re-Export Logger Interface

module System.Logger.Types

Logger

data Logger a

Instances

Generic (Logger a)

LoggerCtx (Logger a) a

Typeable (* -> *) Logger

type Rep (Logger a)

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

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

Configuration Types

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