Control.Eff.Log.Writer

The LogWriter type encapsulates an IO action to write LogMessages.

LogWriter Definition

newtype LogWriter

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

Constructors

MkLogWriter

Fields

• runLogWriter :: LogMessage -> IO ()

Instances

Semigroup LogWriter

Defined in Control.Eff.Log.Writer

Methods

(<>) :: LogWriter -> LogWriter -> LogWriter

sconcat :: NonEmpty LogWriter -> LogWriter

stimes :: Integral b => b -> LogWriter -> LogWriter

Monoid LogWriter

Defined in Control.Eff.Log.Writer

Methods

mempty :: LogWriter

mappend :: LogWriter -> LogWriter -> LogWriter

mconcat :: [LogWriter] -> LogWriter

LogWriter Reader Effect

type LogWriterReader = Reader LogWriter

A Reader effect for LogWriters.

Since: 0.31.0

localLogWriterReader :: forall e a. Member LogWriterReader e => (LogWriter -> LogWriter) -> Eff e a -> Eff e a

Modify the current LogWriter.

askLogWriter :: Member LogWriterReader e => Eff e LogWriter

Get the current LogWriter.

runLogWriterReader :: LogWriter -> Eff (Reader LogWriter ': e) a -> Eff e a

Provide the LogWriter

Exposed for custom extensions, if in doubt use withLogging.

LogWriter utilities

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

Write a message using the LogWriter found in the environment.

noOpLogWriter :: LogWriter

This LogWriter will discard all messages.

NOTE: This is just an alias for mempty

filteringLogWriter :: LogPredicate -> LogWriter -> LogWriter

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 -> LogWriter

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

mappingLogWriterIO :: (LogMessage -> IO LogMessage) -> LogWriter -> LogWriter

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

ioHandleLogWriter :: Handle -> LogMessageRenderer Text -> LogWriter

Append the LogMessage to an Handle after rendering it.

Since: 0.31.0

stdoutLogWriter :: LogMessageRenderer Text -> IO LogWriter

Render a LogMessage to stdout.

This function will also set the BufferMode of stdout to LineBuffering.

See ioHandleLogWriter.

Since: 0.31.0