System.Wlog.CanLog

Type class that add ability to log messages. Supports pure and IO logging.

Documentation

class Monad m => CanLog m where

Instances of this class should explain how they add messages to their log.

Methods

dispatchMessage :: LoggerName -> Severity -> Text -> m ()

dispatchMessage :: (MonadTrans t, t n ~ m, CanLog n) => LoggerName -> Severity -> Text -> t n ()

Instances

CanLog IO

Methods

dispatchMessage :: LoggerName -> Severity -> Text -> IO ()

CanLog m => CanLog (LoggerNameBox m)

Methods

dispatchMessage :: LoggerName -> Severity -> Text -> LoggerNameBox m ()

Monad m => CanLog (PureLogger m)

Methods

dispatchMessage :: LoggerName -> Severity -> Text -> PureLogger m ()

CanLog m => CanLog (StateT s m)

Methods

dispatchMessage :: LoggerName -> Severity -> Text -> StateT s m ()

CanLog m => CanLog (ExceptT s m)

Methods

dispatchMessage :: LoggerName -> Severity -> Text -> ExceptT s m ()

CanLog m => CanLog (ReaderT * r m)

Methods

dispatchMessage :: LoggerName -> Severity -> Text -> ReaderT * r m ()

(CanLog m, Monoid w) => CanLog (RWST r w s m)

Methods

dispatchMessage :: LoggerName -> Severity -> Text -> RWST r w s m ()

(CanLog m, Monoid w) => CanLog (RWST r w s m)

Methods

dispatchMessage :: LoggerName -> Severity -> Text -> RWST r w s m ()

type WithLogger m = (CanLog m, HasLoggerName m)

Type alias for constraints CanLog and HasLoggerName. We need two different type classes to support more flexible interface but in practice we usually use them both.

Pure logging manipulation

newtype PureLogger m a

Pure implementation of CanLog type class. Instead of writing log messages into console it appends log messages into WriterT log. It uses DList for better performance, because messages can be added only at the end of log. But it uses unsafePerformIO so use with caution within IO.

TODO: Should we use some Data.Tree-like structure to observe message only by chosen logger names?

Constructors

PureLogger

Fields

• runPureLogger :: WriterT (DList LogEvent) m a

Instances

MonadTrans PureLogger

Methods

lift :: Monad m => m a -> PureLogger m a

MonadState s m => MonadState s (PureLogger m)

Methods

get :: PureLogger m s

put :: s -> PureLogger m ()

state :: (s -> (a, s)) -> PureLogger m a

MonadReader r m => MonadReader r (PureLogger m)

Methods

ask :: PureLogger m r

local :: (r -> r) -> PureLogger m a -> PureLogger m a

reader :: (r -> a) -> PureLogger m a

MonadError e m => MonadError e (PureLogger m)

Methods

throwError :: e -> PureLogger m a

catchError :: PureLogger m a -> (e -> PureLogger m a) -> PureLogger m a

MonadBase b m => MonadBase b (PureLogger m)

Methods

liftBase :: b α -> PureLogger m α

Monad m => Monad (PureLogger m)

Methods

(>>=) :: PureLogger m a -> (a -> PureLogger m b) -> PureLogger m b

(>>) :: PureLogger m a -> PureLogger m b -> PureLogger m b

return :: a -> PureLogger m a

fail :: String -> PureLogger m a

Functor m => Functor (PureLogger m)

Methods

fmap :: (a -> b) -> PureLogger m a -> PureLogger m b

(<$) :: a -> PureLogger m b -> PureLogger m a

Applicative m => Applicative (PureLogger m)

Methods

pure :: a -> PureLogger m a

(<*>) :: PureLogger m (a -> b) -> PureLogger m a -> PureLogger m b

(*>) :: PureLogger m a -> PureLogger m b -> PureLogger m b

(<*) :: PureLogger m a -> PureLogger m b -> PureLogger m a

(HasLoggerName m, Monad m) => HasLoggerName (PureLogger m)

Methods

getLoggerName :: PureLogger m LoggerName

modifyLoggerName :: (LoggerName -> LoggerName) -> PureLogger m a -> PureLogger m a

Monad m => CanLog (PureLogger m)

Methods

dispatchMessage :: LoggerName -> Severity -> Text -> PureLogger m ()

Monad m => MonadWriter (DList LogEvent) (PureLogger m)

Methods

writer :: (a, DList LogEvent) -> PureLogger m a

tell :: DList LogEvent -> PureLogger m ()

listen :: PureLogger m a -> PureLogger m (a, DList LogEvent)

pass :: PureLogger m (a, DList LogEvent -> DList LogEvent) -> PureLogger m a

data LogEvent

Holds all required information for dispatchLoggerName function.

Constructors

LogEvent

Fields

• leLoggerName :: !LoggerName
• leSeverity :: !Severity
• leMessage :: !Text

Instances

Show LogEvent

Methods

showsPrec :: Int -> LogEvent -> ShowS

show :: LogEvent -> String

showList :: [LogEvent] -> ShowS

SafeCopy LogEvent

Methods

version :: Version LogEvent

kind :: Kind LogEvent

getCopy :: Contained (Get LogEvent)

putCopy :: LogEvent -> Contained Put

internalConsistency :: Consistency LogEvent

objectProfile :: Profile LogEvent

errorTypeName :: Proxy LogEvent -> String

Monad m => MonadWriter (DList LogEvent) (PureLogger m)

Methods

writer :: (a, DList LogEvent) -> PureLogger m a

tell :: DList LogEvent -> PureLogger m ()

listen :: PureLogger m a -> PureLogger m (a, DList LogEvent)

pass :: PureLogger m (a, DList LogEvent -> DList LogEvent) -> PureLogger m a

dispatchEvents :: WithLogger m => [LogEvent] -> m ()

Logs all LogEvent's from given list. This function supposed to be used after runPureLog.

runPureLog :: Monad m => PureLogger m a -> m (a, [LogEvent])

Return log of pure logging action as list of LogEvent.

Logging functions

logDebug :: WithLogger m => Text -> m ()

Shortcut for logMessage to use according severity.

logError :: WithLogger m => Text -> m ()

Shortcut for logMessage to use according severity.

logInfo :: WithLogger m => Text -> m ()

Shortcut for logMessage to use according severity.

logNotice :: WithLogger m => Text -> m ()

Shortcut for logMessage to use according severity.

logWarning :: WithLogger m => Text -> m ()

Shortcut for logMessage to use according severity.

logMessage :: WithLogger m => Severity -> Text -> m ()

Logs message with specified severity using logger name in context.