In case people are interested: although Java and Python both use exceptions, some more recent languages have moved away from exceptions as an approach to error-handling. (For instance, neither Rust nor Go have exceptions.)
A big problem with exceptions is that anytime you call a function or method, in Java, say:
String mystring = audio_recording.getArtist();
then there's often a huge range of exceptions that could be thrown, and you have very little information about what they are - so getArtist() could fail in unpredictable ways at runtime. If getArtist were part of a built-in class for your language, then the exceptions might be fairly well documented - but often the class you're using is part of some third-party library which in turn calls other libraries, any of which could throw their own exceptions.
A second problem is that exceptions often conflate two sorts of errors:
- Functions that can "fail" in known ways (e.g. opening a file can fail due to the file not existing)
- Logic errors (bugs) that occur due to mistakes by the programmer.
If (2) has occurred, then, usually, that's not something we can recover from – the code contains a bug, we've got ourselves into a bad state, and often the best thing we can do is just abort. (Or, sometimes, print a user-friendly message and then abort.)
If (1) has occurred, a way of dealing with this is to allow a method like getArtist to return, say, either a String (if it succeeded), or, say, a MalformedAudio object (if it failed), where MalformedAudio contains information about the failure. This might seem similar to exceptions – a MalformedAudio object is often a lot like how we would implement a MalformedAudioException – but the idea is that the language guarantees that those are the only two options - we can't get other sorts of exception we weren't expecting.
(For an example of an attempt to "back-port" this approach to Java, see for example the Vavr library - it includes a Java Either type, so that methods can indicate they return one type, or another.)
Cheers!
Arran
