Safe Haskell	None
Language	Haskell2010

Control.Eff.Log.Writer

Contents

LogWriter Definition
LogWriter Reader Effect
LogWriter Handler Class
- LogWriter Handler Instance Zoo
- Writer Combinator

Description

The LogWriter type encapsulates an effectful function to write LogMessages.

Used in conjunction with the HandleLogWriter class, it can be used to write messages from within an effectful computation.

Synopsis

newtype LogWriter writerM = MkLogWriter {
- runLogWriter :: LogMessage -> writerM ()
}
data LogWriterReader h v
localLogWriterReader :: forall h e a. SetMember LogWriterReader (LogWriterReader h) e => (LogWriter h -> LogWriter h) -> Eff e a -> Eff e a
askLogWriter :: SetMember LogWriterReader (LogWriterReader h) e => Eff e (LogWriter h)
runLogWriterReader :: LogWriter h -> Eff (LogWriterReader h ': e) a -> Eff e a
class HandleLogWriter (writerEff :: Type -> Type) where
- type LogWriterEffects writerEff :: [Type -> Type]
- handleLogWriterEffect :: LogWriterEffects writerEff <:: e => writerEff () -> Eff e ()
- liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader writerEff) e, LogWriterEffects writerEff <:: e) => LogMessage -> Eff e ()
noOpLogWriter :: Applicative m => LogWriter m
debugTraceLogWriter :: Monad h => LogWriter h
newtype PureLogWriter a = MkPureLogWriter {
- runPureLogWriter :: Identity a
}
listLogWriter :: LogWriter CaptureLogs
newtype CaptureLogs a = MkCaptureLogs {
- unCaptureLogs :: Eff '[CapturedLogsWriter] a
}
type CapturedLogsWriter = Writer LogMessage
runCapturedLogsWriter :: Eff (CapturedLogsWriter ': e) a -> Eff e (a, [LogMessage])
consoleLogWriter :: LogWriter IO
ioHandleLogWriter :: HasCallStack => Handle -> LogWriter IO
filteringLogWriter :: Monad e => LogPredicate -> LogWriter e -> LogWriter e
mappingLogWriter :: (LogMessage -> LogMessage) -> LogWriter e -> LogWriter e
mappingLogWriterM :: Monad e => (LogMessage -> e LogMessage) -> LogWriter e -> LogWriter e
ioLogWriter :: HasCallStack => (LogMessage -> IO ()) -> LogWriter IO
defaultIoLogWriter :: String -> Facility -> LogWriter IO -> LogWriter IO

`LogWriter` Definition

newtype LogWriter writerM Source #

A function that takes a log message and returns an effect that logs the message.

Constructors

MkLogWriter
Fields runLogWriter :: LogMessage -> writerM ()

Instances

Applicative w => Default (LogWriter w) Source #
Instance details Defined in Control.Eff.Log.Writer Methods def :: LogWriter w #
Handle (LogWriterReader h) e a (LogWriter h -> k) Source #
Instance details Defined in Control.Eff.Log.Writer Methods handle :: (Eff e a -> LogWriter h -> k) -> Arrs e v a -> LogWriterReader h v -> LogWriter h -> k # handle_relay :: (e ~ (LogWriterReader h ': r'), Relay (LogWriter h -> k) r') => (a -> LogWriter h -> k) -> (Eff e a -> LogWriter h -> k) -> Eff e a -> LogWriter h -> k # respond_relay :: (a -> LogWriter h -> k) -> (Eff e a -> LogWriter h -> k) -> Eff e a -> LogWriter h -> k #

LogWriter Reader Effect

data LogWriterReader h v Source #

A Reader specialized for LogWriters

The existing Reader couldn't be used together with SetMember, so this lazy reader was written, specialized to reading LogWriter.

Instances

(MonadBase m m, LiftedBase m r) => MonadBaseControl m (Eff (LogWriterReader h ': r)) Source #
Instance details Defined in Control.Eff.Log.Writer Associated Types type StM (Eff (LogWriterReader h ': r)) a :: Type # Methods liftBaseWith :: (RunInBase (Eff (LogWriterReader h ': r)) m -> m a) -> Eff (LogWriterReader h ': r) a # restoreM :: StM (Eff (LogWriterReader h ': r)) a -> Eff (LogWriterReader h ': r) a #
(LiftedBase m e, MonadThrow (Eff e)) => MonadThrow (Eff (LogWriterReader h ': e)) Source #
Instance details Defined in Control.Eff.Log.Writer Methods throwM :: Exception e0 => e0 -> Eff (LogWriterReader h ': e) a #
(Applicative m, LiftedBase m e, MonadCatch (Eff e)) => MonadCatch (Eff (LogWriterReader h ': e)) Source #
Instance details Defined in Control.Eff.Log.Writer Methods catch :: Exception e0 => Eff (LogWriterReader h ': e) a -> (e0 -> Eff (LogWriterReader h ': e) a) -> Eff (LogWriterReader h ': e) a #
(Applicative m, LiftedBase m e, MonadMask (Eff e)) => MonadMask (Eff (LogWriterReader h ': e)) Source #
Instance details Defined in Control.Eff.Log.Writer Methods mask :: ((forall a. Eff (LogWriterReader h ': e) a -> Eff (LogWriterReader h ': e) a) -> Eff (LogWriterReader h ': e) b) -> Eff (LogWriterReader h ': e) b # uninterruptibleMask :: ((forall a. Eff (LogWriterReader h ': e) a -> Eff (LogWriterReader h ': e) a) -> Eff (LogWriterReader h ': e) b) -> Eff (LogWriterReader h ': e) b # generalBracket :: Eff (LogWriterReader h ': e) a -> (a -> ExitCase b -> Eff (LogWriterReader h ': e) c) -> (a -> Eff (LogWriterReader h ': e) b) -> Eff (LogWriterReader h ': e) (b, c) #
Handle (LogWriterReader h) e a (LogWriter h -> k) Source #
Instance details Defined in Control.Eff.Log.Writer Methods handle :: (Eff e a -> LogWriter h -> k) -> Arrs e v a -> LogWriterReader h v -> LogWriter h -> k # handle_relay :: (e ~ (LogWriterReader h ': r'), Relay (LogWriter h -> k) r') => (a -> LogWriter h -> k) -> (Eff e a -> LogWriter h -> k) -> Eff e a -> LogWriter h -> k # respond_relay :: (a -> LogWriter h -> k) -> (Eff e a -> LogWriter h -> k) -> Eff e a -> LogWriter h -> k #
type StM (Eff (LogWriterReader h ': r)) a Source #
Instance details Defined in Control.Eff.Log.Writer type StM (Eff (LogWriterReader h ': r)) a = StM (Eff r) a

localLogWriterReader :: forall h e a. SetMember LogWriterReader (LogWriterReader h) e => (LogWriter h -> LogWriter h) -> Eff e a -> Eff e a Source #

Modify the current LogWriter.

askLogWriter :: SetMember LogWriterReader (LogWriterReader h) e => Eff e (LogWriter h) Source #

Get the current LogWriter.

runLogWriterReader :: LogWriter h -> Eff (LogWriterReader h ': e) a -> Eff e a Source #

Provide the LogWriter

Exposed for custom extensions, if in doubt use withLogging.

LogWriter Handler Class

class HandleLogWriter (writerEff :: Type -> Type) where Source #

The instances of this class are the monads that define (side-) effect(s) of writting logs.

Minimal complete definition

handleLogWriterEffect

Associated Types

type LogWriterEffects writerEff :: [Type -> Type] Source #

A list of effects that are required for writing the log messages. For example 'Lift IO' or '[]' for pure log writers.

Methods

handleLogWriterEffect :: LogWriterEffects writerEff <:: e => writerEff () -> Eff e () Source #

Run the side effect of a LogWriter in a compatible Eff.

liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader writerEff) e, LogWriterEffects writerEff <:: e) => LogMessage -> Eff e () Source #

Write a message using the LogWriter found in the environment.

The semantics of this function are a combination of runLogWriter and handleLogWriterEffect, with the LogWriter read from a LogWriterReader.

Instances

HandleLogWriter IO Source #
Instance details Defined in Control.Eff.Log.Writer Associated Types type LogWriterEffects IO :: [Type -> Type] Source # Methods handleLogWriterEffect :: LogWriterEffects IO <:: e => IO () -> Eff e () Source # liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader IO) e, LogWriterEffects IO <:: e) => LogMessage -> Eff e () Source #
HandleLogWriter CaptureLogs Source #	A `LogWriter` monad for pure logging. The `HandleLogWriter` instance for this type assumes a `Writer` effect.
Instance details Defined in Control.Eff.Log.Writer Associated Types type LogWriterEffects CaptureLogs :: [Type -> Type] Source # Methods handleLogWriterEffect :: LogWriterEffects CaptureLogs <:: e => CaptureLogs () -> Eff e () Source # liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader CaptureLogs) e, LogWriterEffects CaptureLogs <:: e) => LogMessage -> Eff e () Source #
HandleLogWriter PureLogWriter Source #	A `LogWriter` monad for `Trace` based pure logging.
Instance details Defined in Control.Eff.Log.Writer Associated Types type LogWriterEffects PureLogWriter :: [Type -> Type] Source # Methods handleLogWriterEffect :: LogWriterEffects PureLogWriter <:: e => PureLogWriter () -> Eff e () Source # liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader PureLogWriter) e, LogWriterEffects PureLogWriter <:: e) => LogMessage -> Eff e () Source #

`LogWriter` Handler Instance Zoo

Pure Writer

noOpLogWriter :: Applicative m => LogWriter m Source #

This LogWriter will discard all messages.

NOTE: This is just an alias for def

debugTraceLogWriter :: Monad h => LogWriter h Source #

A LogWriter that applies renderLogMessage to the log message and then traces it using traceM. This LogWriter work with any base monad.

newtype PureLogWriter a Source #

A phantom type for the HandleLogWriter class for pure LogWriters

Constructors

MkPureLogWriter
Fields runPureLogWriter :: Identity a

Instances

Monad PureLogWriter Source #
Instance details Defined in Control.Eff.Log.Writer Methods (>>=) :: PureLogWriter a -> (a -> PureLogWriter b) -> PureLogWriter b # (>>) :: PureLogWriter a -> PureLogWriter b -> PureLogWriter b # return :: a -> PureLogWriter a # fail :: String -> PureLogWriter a #
Functor PureLogWriter Source #
Instance details Defined in Control.Eff.Log.Writer Methods fmap :: (a -> b) -> PureLogWriter a -> PureLogWriter b # (<$) :: a -> PureLogWriter b -> PureLogWriter a #
Applicative PureLogWriter Source #
Instance details Defined in Control.Eff.Log.Writer Methods pure :: a -> PureLogWriter a # (<>) :: PureLogWriter (a -> b) -> PureLogWriter a -> PureLogWriter b # liftA2 :: (a -> b -> c) -> PureLogWriter a -> PureLogWriter b -> PureLogWriter c # (>) :: PureLogWriter a -> PureLogWriter b -> PureLogWriter b # (<*) :: PureLogWriter a -> PureLogWriter b -> PureLogWriter a #
HandleLogWriter PureLogWriter Source #	A `LogWriter` monad for `Trace` based pure logging.
Instance details Defined in Control.Eff.Log.Writer Associated Types type LogWriterEffects PureLogWriter :: [Type -> Type] Source # Methods handleLogWriterEffect :: LogWriterEffects PureLogWriter <:: e => PureLogWriter () -> Eff e () Source # liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader PureLogWriter) e, LogWriterEffects PureLogWriter <:: e) => LogMessage -> Eff e () Source #
type LogWriterEffects PureLogWriter Source #
Instance details Defined in Control.Eff.Log.Writer type LogWriterEffects PureLogWriter = ([] :: [Type -> Type])

List Writer

listLogWriter :: LogWriter CaptureLogs Source #

A LogWriter monad that provides pure logging by capturing via the Writer effect.

newtype CaptureLogs a Source #

A LogWriter monad that provides pure logging by capturing via the Writer effect.

Constructors

MkCaptureLogs
Fields unCaptureLogs :: Eff '[CapturedLogsWriter] a

Instances

Monad CaptureLogs Source #
Instance details Defined in Control.Eff.Log.Writer Methods (>>=) :: CaptureLogs a -> (a -> CaptureLogs b) -> CaptureLogs b # (>>) :: CaptureLogs a -> CaptureLogs b -> CaptureLogs b # return :: a -> CaptureLogs a # fail :: String -> CaptureLogs a #
Functor CaptureLogs Source #
Instance details Defined in Control.Eff.Log.Writer Methods fmap :: (a -> b) -> CaptureLogs a -> CaptureLogs b # (<$) :: a -> CaptureLogs b -> CaptureLogs a #
Applicative CaptureLogs Source #
Instance details Defined in Control.Eff.Log.Writer Methods pure :: a -> CaptureLogs a # (<>) :: CaptureLogs (a -> b) -> CaptureLogs a -> CaptureLogs b # liftA2 :: (a -> b -> c) -> CaptureLogs a -> CaptureLogs b -> CaptureLogs c # (>) :: CaptureLogs a -> CaptureLogs b -> CaptureLogs b # (<*) :: CaptureLogs a -> CaptureLogs b -> CaptureLogs a #
HandleLogWriter CaptureLogs Source #	A `LogWriter` monad for pure logging. The `HandleLogWriter` instance for this type assumes a `Writer` effect.
Instance details Defined in Control.Eff.Log.Writer Associated Types type LogWriterEffects CaptureLogs :: [Type -> Type] Source # Methods handleLogWriterEffect :: LogWriterEffects CaptureLogs <:: e => CaptureLogs () -> Eff e () Source # liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader CaptureLogs) e, LogWriterEffects CaptureLogs <:: e) => LogMessage -> Eff e () Source #
type LogWriterEffects CaptureLogs Source #
Instance details Defined in Control.Eff.Log.Writer type LogWriterEffects CaptureLogs = CapturedLogsWriter ': ([] :: [Type -> Type])

type CapturedLogsWriter = Writer LogMessage Source #

Alias for the Writer that contains the captured LogMessages from CaptureLogs.

runCapturedLogsWriter :: Eff (CapturedLogsWriter ': e) a -> Eff e (a, [LogMessage]) Source #

Run a Writer for LogMessages.

Such a Writer is needed for CaptureLogs

IO Writer

consoleLogWriter :: LogWriter IO Source #

Write LogMessages to standard output, formatted with printLogMessage.

ioHandleLogWriter :: HasCallStack => Handle -> LogWriter IO Source #

A LogWriter that renders LogMessages to strings via renderLogMessage and prints them to an Handle using hPutStrLn.

Writer Combinator

Pure Writer Combinator

filteringLogWriter :: Monad e => LogPredicate -> LogWriter e -> LogWriter e Source #

A LogWriter that applies a predicate to the LogMessage and delegates to to the given writer of the predicate is satisfied.

mappingLogWriter :: (LogMessage -> LogMessage) -> LogWriter e -> LogWriter e Source #

A LogWriter that applies a function to the LogMessage and delegates the result to to the given writer.

Impure Writer Combinator

mappingLogWriterM :: Monad e => (LogMessage -> e LogMessage) -> LogWriter e -> LogWriter e Source #

Like mappingLogWriter allow the function that changes the LogMessage to have effects.

IO Based Combinator

ioLogWriter :: HasCallStack => (LogMessage -> IO ()) -> LogWriter IO Source #

A LogWriter that uses an IO action to write the message.

Example use cases for this function are the consoleLogWriter and the ioHandleLogWriter.

defaultIoLogWriter Source #

Arguments

:: String	The default application name to put into the `lmAppName` field.
-> Facility	The default RFC-5424 facility to put into the `lmFacility` field.
-> LogWriter IO	The IO based writer to decorate
-> LogWriter IO

Decorate an IO based LogWriter to fill out these fields in LogMessages:

The messages will carry the given application name in the lmAppName field.
The lmTimestamp field contains the UTC time of the log event
The lmThreadId field contains the thread-Id
The lmHostname field contains the FQDN of the current host
The lmFacility field contains the given Facility

It works by using mappingLogWriterM.

LogWriter Definition

LogWriter Reader Effect

LogWriter Handler Class

LogWriter Handler Instance Zoo

Pure Writer

List Writer

IO Writer

Writer Combinator

Pure Writer Combinator

Impure Writer Combinator

IO Based Combinator

`LogWriter` Definition

`LogWriter` Handler Instance Zoo