Revision 88a10df5 htools/Ganeti/BasicTypes.hs

b/htools/Ganeti/BasicTypes.hs
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  , eitherToResult
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  , annotateResult
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  , annotateIOError
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  , exitIfBad
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  ) where
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import Control.Monad


  		





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import System.IO (hPutStrLn, stderr)


  		





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import System.Exit


  		





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-- | This is similar to the JSON library Result type - /very/ similar,


  		





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-- but we want to use it in multiple places, so we abstract it into a


  		





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annotateIOError :: String -> IOError -> IO (Result a)


  		





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annotateIOError description exc =


  		





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  return . Bad $ description ++ ": " ++ show exc


  		





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-- | Unwraps a 'Result', exiting the program if it is a 'Bad' value,


  		





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-- otherwise returning the actual contained value.


  		





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exitIfBad :: Result a -> IO a


  		





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exitIfBad (Bad s) = do


  		





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  hPutStrLn stderr $ "Failure: " ++ s


  		





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  exitWith (ExitFailure 1)


  		





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exitIfBad (Ok v) = return v


  		












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