The async-refresh package

This is a package candidate release! Here you can preview how this package release will appear once published to the main package index (which can be accomplished via the 'maintain' link below). Please note that once a package has been published to the main package index it cannot be undone! Please consult the package uploading documentation for more information.


This package can be used for refreshing of expiring data according to a user-provided action. Using callbacks, the user can decide how she or he would like to be informed about data refreshing.

[Skip to ReadMe]


Versions0.1.7, 0.2.0, 0.2.0
Change logNone available
Dependenciesbase (>=4.7 && <5), formatting, lens, lifted-async, monad-control, monad-logger, safe-exceptions, stm, text [details]
Copyright(c) 2017 Moritz Schulte
AuthorMoritz Schulte
Home page
Source repositoryhead: git clone
UploadedTue Apr 11 14:18:42 UTC 2017 by mtesseract



Maintainers' corner

For package maintainers and hackage trustees

Readme for async-refresh-0.2.0



This is Haskell library implementing the logic for refreshing of expiring data according to user-provided actions.



The following IO action produces a TVar which is updated every ten seconds to contain the current time (wrapped in an Either SomeException, because refreshing may fail).

periodicTimeUpdater :: IO (TVar (Either SomeException UTCTime))
periodicTimeUpdater = runStderrLoggingT $ do
  timeStore <- liftIO $ newTVarIO (Left (toException NotFound))
  let conf = newAsyncRefreshConf (RefreshResult <$> liftIO getCurrentTime <*> pure Nothing)
        & asyncRefreshConfSetLabel "CurrentTime updated every 10 seconds"
        & asyncRefreshConfSetDefaultInterval (10 * 10^3)
        & asyncRefreshConfSetCallback (liftIO . atomically . writeTVar timeStore . fmap refreshResult)
  _ <- newAsyncRefresh conf
  return timeStore