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 -> LogWriterM writerM ()

Instances

Applicative (LogWriterM 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 (writer :: Type -> Type) where

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

Minimal complete definition

handleLogWriterEffect

Associated Types

data LogWriterM writer a

The Effects required by the handleLogWriterEffect method.

Since: 0.29.1

Methods

handleLogWriterEffect :: Member writer e => LogWriterM writer () -> Eff e ()

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

liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader writer) e, Member writer 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

HandleLogWriter Logs

This instance is for pure logging - i.e. discarding all messages.

Since: 0.29.1

Defined in Control.Eff.Log.Handler

Associated Types

data LogWriterM Logs a :: Type

Methods

handleLogWriterEffect :: Member Logs e => LogWriterM Logs () -> Eff e ()

liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader Logs) e, Member Logs e) => LogMessage -> Eff e ()

HandleLogWriter (Writer LogMessage)

A LogWriter monad for capturing messages using a Writer.

The HandleLogWriter instance for this type assumes a Writer effect.

Defined in Control.Eff.Log.Writer

Associated Types

data LogWriterM (Writer LogMessage) a :: Type

Methods

handleLogWriterEffect :: Member (Writer LogMessage) e => LogWriterM (Writer LogMessage) () -> Eff e ()

liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader (Writer LogMessage)) e, Member (Writer LogMessage) e) => LogMessage -> Eff e ()

HandleLogWriter (Lift IO)

Embed IO actions consuming all LogMessages

Since: 0.29.1

Defined in Control.Eff.Log.Writer

Associated Types

data LogWriterM (Lift IO) a :: Type

Methods

handleLogWriterEffect :: Member (Lift IO) e => LogWriterM (Lift IO) () -> Eff e ()

liftWriteLogMessage :: (SetMember LogWriterReader (LogWriterReader (Lift IO)) e, Member (Lift IO) e) => LogMessage -> Eff e ()

noOpLogWriter :: Applicative (LogWriterM m) => LogWriter m

This LogWriter will discard all messages.

NOTE: This is just an alias for def

Writer Combinator

Pure Writer Combinator

filteringLogWriter :: Monad (LogWriterM 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 (LogWriterM e) => (LogMessage -> LogWriterM e LogMessage) -> LogWriter e -> LogWriter e

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