Michael Snoyman
shouldBeCaught :: SomeException -> Bool
One first stab at such a function would be to return `False` for AsyncException and Timeout, and `True` for everything else, but I'm not convinced that this is sufficient. Are there any thoughts on the right approach to take here?
I think there is no one right approach. However, if you add such a function to the exception library, it really belongs into the Exception type class with the following type: shouldBeCaught :: (Exception e) => e -> Bool However, a better approach is to have exception tags. In most cases you don't want to catch killThread's or timeout's exception, but you do want to catch all error exceptions: data Tag = Error | Abort | TryAgain | {- ... -} | Other String deriving (Data, Eq, Ord, Read, Show, Typeable) instance IsString Tag where fromString t = Other t This could then manifest in the following two functions in the Exception type class: hasTag :: (Exception e) => Tag -> e -> Bool tagsOf :: (Exception e) => e -> [Tag] Then exception catchers (functions that risk swallowing important exceptions) could filter by type and tag. Greets, Ertugrul -- Not to be or to be and (not to be or to be and (not to be or to be and (not to be or to be and ... that is the list monad.