Control.Eff.Log.Writer

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.

LogWriter Definition

newtype LogWriter writerM

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)

Defined in Control.Eff.Log.Writer

Methods

def :: LogWriter w

Handle (LogWriterReader h) e a (LogWriter h -> k)

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

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))

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))

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))

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))

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)

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

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

Modify the current LogWriter.

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

Get the current LogWriter.

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

Provide the LogWriter

Exposed for custom extensions, if in doubt use withLogging.

LogWriter Handler Class

class HandleLogWriter (writerEff :: Type -> Type) e where

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

Minimal complete definition

handleLogWriterEffect

Methods

handleLogWriterEffect :: writerEff () -> Eff e ()

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

liftWriteLogMessage :: SetMember LogWriterReader (LogWriterReader writerEff) e => LogMessage -> Eff e ()

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

Lifted IO e => HandleLogWriter IO e

Defined in Control.Eff.Log.Writer

Methods

handleLogWriterEffect :: IO () -> Eff e ()

liftWriteLogMessage :: LogMessage -> Eff e ()

HandleLogWriter PureLogWriter e

A LogWriter monad for Trace based pure logging.

Defined in Control.Eff.Log.Writer

Methods

handleLogWriterEffect :: PureLogWriter () -> Eff e ()

liftWriteLogMessage :: LogMessage -> Eff e ()

Member CaptureLogWriter e => HandleLogWriter CaptureLogs e

A LogWriter monad for pure logging.

The HandleLogWriter instance for this type assumes a Writer effect.

Defined in Control.Eff.LogWriter.Capture

Methods

handleLogWriterEffect :: CaptureLogs () -> Eff e ()

liftWriteLogMessage :: LogMessage -> Eff e ()

noOpLogWriter :: Applicative m => LogWriter m

This LogWriter will discard all messages.

NOTE: This is just an alias for def

newtype PureLogWriter a

A phantom type for the HandleLogWriter class for pure LogWriters

Constructors

MkPureLogWriter

Fields

• runPureLogWriter :: Identity a

Instances

Monad PureLogWriter

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

Defined in Control.Eff.Log.Writer

Methods

fmap :: (a -> b) -> PureLogWriter a -> PureLogWriter b

(<$) :: a -> PureLogWriter b -> PureLogWriter a

Applicative PureLogWriter

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 e

A LogWriter monad for Trace based pure logging.

Defined in Control.Eff.Log.Writer

Methods

handleLogWriterEffect :: PureLogWriter () -> Eff e ()

liftWriteLogMessage :: LogMessage -> Eff e ()

Writer Combinator

Pure Writer Combinator

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

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

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

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