Andreas-Haskell:

Hi!

In module Control.Exception there are the exception predicates errorCalls and userErrors defined. Is there any difference between them? Which one?

They match different kinds of exceptions, errorCalls (ErrorCall e) = Just e errorCalls _ = Nothing assertions (AssertionFailed e) = Just e assertions _ = Nothing dynExceptions (DynException e) = Just e dynExceptions _ = Nothing asyncExceptions (AsyncException e) = Just e asyncExceptions _ = Nothing userErrors (IOException e) | isUserError e = Just (ioeGetErrorString e) userErrors _ = Nothing The 'Awkward Squad' paper should have some details. The various papers on exceptions should also help (see the 'Research papers' page on the Haskell wiki). -- Don