displayException is never used
The typeclass method
displayException is not used. This should be remedied by either:
- Documenting that it does not get used anywhere (implies that there is no point in overriding the default)
- Using it (in
base) when displaying exceptions.
Steps to reproduce
Here is an example that demonstrates that
displayException is not used:
import Control.Exception main :: IO () main = throwIO MyException data MyException = MyException deriving (Show,Eq) instance Exception MyException where displayException _ = "custom-my-exception-display"
Running this results in:
$ ./example-exception example-exception: MyException
I would expect to see:
amartin@thadtop:~/Development/test$ ./example-exception example-exception: custom-my-exception-display