diff options
Diffstat (limited to 'Annex/Exception.hs')
| -rw-r--r-- | Annex/Exception.hs | 29 |
1 files changed, 15 insertions, 14 deletions
diff --git a/Annex/Exception.hs b/Annex/Exception.hs index de6a23611..f06f568a4 100644 --- a/Annex/Exception.hs +++ b/Annex/Exception.hs @@ -1,36 +1,37 @@ {- exception handling in the git-annex monad - - - Copyright 2011 Joey Hess <joey@kitenet.net> + - Note that when an Annex action fails and the exception is handled + - by these functions, any changes the action has made to the + - AnnexState are retained. This works because the Annex monad + - internally stores the AnnexState in a MVar. + - + - Copyright 2011-2013 Joey Hess <joey@kitenet.net> - - Licensed under the GNU GPL version 3 or higher. -} module Annex.Exception ( bracketIO, - handle, tryAnnex, throw, + catchAnnex, ) where -import Control.Exception.Lifted (handle, try) -import Control.Monad.Trans.Control (liftBaseOp) -import Control.Exception hiding (handle, try, throw) +import Prelude hiding (catch) +import "MonadCatchIO-transformers" Control.Monad.CatchIO (bracket, try, throw, catch) +import Control.Exception hiding (handle, try, throw, bracket, catch) import Common.Annex -{- Runs an Annex action, with setup and cleanup both in the IO monad. - - - - Warning: Currently if the Annex action fails, any changes it has made - - to Annex state are discarded. - -} +{- Runs an Annex action, with setup and cleanup both in the IO monad. -} bracketIO :: IO c -> (c -> IO b) -> Annex a -> Annex a bracketIO setup cleanup go = - liftBaseOp (Control.Exception.bracket setup cleanup) (const go) + bracket (liftIO setup) (liftIO . cleanup) (const go) {- try in the Annex monad -} tryAnnex :: Annex a -> Annex (Either SomeException a) tryAnnex = try -{- Throws an exception in the Annex monad. -} -throw :: Control.Exception.Exception e => e -> Annex a -throw = liftIO . throwIO +{- catch in the Annex monad -} +catchAnnex :: Exception e => Annex a -> (e -> Annex a) -> Annex a +catchAnnex = catch |