On Sun, May 3, 2009 at 6:36 PM, <br...@lorf.org> wrote: > I wrote this to make it a little nicer to catch IO exceptions and > convert them to ErrorT failure: > > onExceptionThrowError > :: (Error ce) => > IO a > -> (String -> ce) > -> ErrorT ce IO a > onExceptionThrowError a ce = > liftIO (try a) >>= > either > (\(e :: IOException) -> throwError (ce (show e))) > return > > So now I can do, e.g., > writeFile fp s `onExceptionThrowError` SpecificErrorConstructor ... > > It works, but seems bad. Please let me know if you see ways to improve > it. Thanks.
What about this? liftCatch :: (IOException -> e) -> IO a -> ErrorT e IO a liftCatch f m = ErrorT $ liftM (either (Left . f) Right) (try m) -- Dave Menendez <d...@zednenem.com> <http://www.eyrie.org/~zednenem/> _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
