Unclog.Subscriber

subscribing to a log channel

newtype Subscriber (m :: Type -> Type)

a Subscriber is something that can observe log entries and do something with them in the Monad m

Constructors

MkSubscriber

Fields

• runSubscriber :: Codensity m (LogEntry -> m ())

colourSubscriber

Arguments

:: forall (m :: Type -> Type). MonadIO m

=> LogLevel

the lowest loglevel to still log

-> Handle

the handle to log to

-> Subscriber m

write a log entry to a handle, printing all information, but use colour

simpleSubscriber

Arguments

:: forall (m :: Type -> Type). MonadIO m

=> LogLevel

the lowest loglevel to still log

-> Handle

the handle to log to

-> Subscriber m

write a log entry to a handle, printing all information

fileSubscriber

Arguments

:: forall (m :: Type -> Type). MonadUnliftIO m

=> LogLevel

the lowest loglevel to still log

-> FilePath

the file to log (append) to

-> Subscriber m

create a simple subscriber that writes to a file

run a logging situation

withLoggingWithSubscribers

Arguments

:: MonadUnliftIO m

=> [Subscriber m]

a list of subscribers

-> (PLogChan -> m r)

a channel, a client can write to

-> m r

it is not a priori unsafe to escape the chan out of the context, it will just mean that all the subscribers are gone and nothing is logged anymore

creating, subscribing and reading from channels

newLogChan :: STM PLogChan

create a new LogChan

newLogChanIO :: MonadIO m => m PLogChan

create a new LogChan in IO

subscribeLog :: PLogChan -> STM SLogChan

subscribe to a publishing log chan to obtain a subscriber log chan

readLogEntry :: SLogChan -> STM LogEntry

read one log entry from a subscriber log chan

helpers

withSubscriber :: Subscriber m -> ((LogEntry -> m ()) -> m b) -> m b

destruct a subscriber

mkSubscriber :: (forall r. ((LogEntry -> m ()) -> m r) -> m r) -> Subscriber m

make a subscriber with a possible clean up (useful if you need to bracket your subscriber)

mkSubscriberSimple :: (LogEntry -> m ()) -> Subscriber m

make a subscriber from a simple log function

bracketSubscriber

Arguments

:: MonadUnliftIO m

=> m a

acquire the resource

-> (a -> m b)

release the resource

-> (a -> LogEntry -> m ())

how to write a log entry given a resource

-> Subscriber m

build a subscriber that requires a resource

refSubscriber :: forall (m :: Type -> Type). MonadIO m => IORef [LogEntry] -> Subscriber m

write log entries to an IORef