Network.firstSuccesful: 'throw' vs 'throwIO' usage
Herbert Valerio Riedel
hvr at gnu.org
Thu Sep 6 11:40:23 CEST 2012
while reading over the source code of network, I noticed a use of 'throw' where I'd
import qualified Control.Exception as Exception
catchIO :: IO a -> (Exception.IOException -> IO a) -> IO a
catchIO = Exception.catch
-- Returns the first action from a list which does not throw an exception.
-- If all the actions throw exceptions (and the list of actions is not empty),
-- the last exception is thrown.
firstSuccessful :: [IO a] -> IO a
firstSuccessful  = error "firstSuccessful: empty list"
firstSuccessful (p:ps) = catchIO p $ \e ->
case ps of
 -> Exception.throw e
_ -> firstSuccessful ps
...so, is `throw` used properly in the code above, or should it rather
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