[Haskell-cafe] Extensible Exceptions

Hi, All. I am trying to understand the new exceptions package in base-4 Control.Exceptions. The documentation for catchJust is the same as in Control.OldException including this example: result <- catchJust errorCalls thing_to_try handler Control.OldException provides the predicate errorCalls, but the new one does not. I don't see how to write it. Thanks for reading. Cheers, David