[Haskell] Catching error / making library functions monadic (in failure)

[Martijn van Steenbergen]

Hi Philip,

Philip K.F. Hölzenspies wrote:
> some_catch_function (error "foo") (error "bar")
> 
> should result in an error "bar"

Take a look at the isBottom function which is defined in module 
Test.QuickCheck.Batch; it might be of value to you:

isBottom :: a -> Bool
isBottom a = unsafePerformIO (do
	a' <- try (Exception.evaluate a)
	case a' of
	   Left _ -> return True
	   Right _ -> return False)

Regards,

Martijn.