Control.Logging

Quick example of how to use this module:

import Control.Logging

main = withStdoutLogging $ do
     log This is a log message!
     timedLog This is a timed log message! $ threadDelay 100000

Documentation

log :: MonadLogger m => Text -> m ()

Synonym for logInfoN. This module provides a MonadLogger instance for IO, so this function can be used directly in IO. The only requirement is that you must surround the body of your main function with a call to withStdoutLogging or withStderrLogging, to ensure that all logging buffers are properly flushed on exit.

log' :: (MonadLogger m, MonadIO m) => Text -> m ()

The apostrophe varients of the logging functions flush the log after each message.

logS :: MonadLogger m => Text -> Text -> m ()

logS' :: (MonadLogger m, MonadIO m) => Text -> Text -> m ()

warn :: MonadLogger m => Text -> m ()

warn' :: (MonadLogger m, MonadIO m) => Text -> m ()

warnS :: MonadLogger m => Text -> Text -> m ()

warnS' :: (MonadLogger m, MonadIO m) => Text -> Text -> m ()

debug :: MonadLogger m => Text -> m ()

debug' :: (MonadLogger m, MonadIO m) => Text -> m ()

debugS :: MonadLogger m => Text -> Text -> m ()

debugS' :: (MonadLogger m, MonadIO m) => Text -> Text -> m ()

errorL :: Text -> a

A logging variant of error which uses unsafePerformIO to output a log message before calling error.

errorL' :: Text -> a

errorSL :: Text -> Text -> a

errorSL' :: Text -> Text -> a

traceL :: Text -> a -> a

traceL' :: Text -> a -> a

traceSL :: Text -> Text -> a -> a

traceSL' :: Text -> Text -> a -> a

traceShowL :: Show a => a -> a1 -> a1

traceShowL' :: Show a => a -> a1 -> a1

traceShowSL :: Show a => Text -> a -> a1 -> a1

traceShowSL' :: Show a => Text -> a -> a1 -> a1

timedLog :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> m () -> m ()

Output a logging message both before an action begins, and after it ends, reporting the total length of time. If an exception occurred, it is also reported.

timedLog' :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> m () -> m ()

timedLogS :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> Text -> m () -> m ()

timedLogS' :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> Text -> m () -> m ()

timedLogEnd :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> m () -> m ()

Like timedLog, except that it does only logs when the action has completed or failed after it is done.

timedLogEnd' :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> m () -> m ()

timedLogEndS :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> Text -> m () -> m ()

timedLogEndS' :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> Text -> m () -> m ()

timedDebug :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> m () -> m ()

A debug variant of timedLog.

timedDebug' :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> m () -> m ()

timedDebugS :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> Text -> m () -> m ()

timedDebugS' :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> Text -> m () -> m ()

timedDebugEnd :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> m () -> m ()

timedDebugEnd' :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> m () -> m ()

timedDebugEndS :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> Text -> m () -> m ()

timedDebugEndS' :: (MonadLogger m, MonadBaseControl IO m, MonadIO m) => Text -> Text -> m () -> m ()

withStdoutLogging :: (MonadBaseControl IO m, MonadIO m) => m a -> m a

This function, or withStderrLogging, must be wrapped around whatever region of your application intends to use logging. Typically it would be wrapped around the body of main.

withStderrLogging :: (MonadBaseControl IO m, MonadIO m) => m a -> m a

flushLog :: MonadIO m => m ()

Flush all collected logging messages. This is automatically called by withStdoutLogging and withStderrLogging when those blocks are exited by whatever means.

loggingLogger :: ToLogStr msg => Loc -> LogSource -> LogLevel -> msg -> IO ()

This function is used to implement monadLoggerLog for the IO instance. You may reuse it if you wish, or it can be passed as an argument to runLoggingT -- in which case you must remember to call flushLog before the program exits.

setDebugLevel :: LogLevel -> IO ()

Set the verbosity level. Messages at our higher than this level are displayed. It defaults to LevelDebug.

setLogFormat :: String -> IO ()

Set the format used for log timestamps.

setDebugSourceRegexp :: String -> IO ()