[gregwebs]

Panic is hidden and not composable.

Composition: Errors as values means it is easy to write functions to deal with them. Errors as exceptions means invoking special language constructs. And program termination doesn't compose well. Library authors always avoid panics. Generally only applications are good at deciding when to panic and when to catch a panic.

Hidden: how do you know if a function panics? If it returns an error, I see that in the type signature and I can be forced to handle it by linting tools. People seem to not like Javas checked exceptions, but I think that like most things Java it had to do with some of the implementation details, I think the concept is much preferable to hidden exceptions/panics.