[Too]

>>The instant an exception can be raised from an area in code is the instant you need to make that entire area into functionally-pure side-effect-free logic, so that you can reason about it even when the exception is raised.

Great insight. But i would say that explicit error handling doesn't help you much there. Side effects are hard and side effects can by nature normally not be reverted anyway. Deleted a file? Tough luck getting it back. IO and external interfaces could also be an issue, wrote 50% of a file to USB-stick when the user yanked it from the port? No amount of explicit error handling will help you remove it there.