Thanks for the answer. It sounds like pretty much the same thing good exception handling would do.
I suppose they're two sides of the same coin. Both can be done well or poorly.
I do resent the idea that error values are automatically better or easier to understand, because I'm dealing with some poorly done error values now and wishing for traditional exception handling.
I guess the differences I see are between "with exceptions, you can accidentally forget to handle the errors in the right place, and you end up handling them elsewhere" vs "with error values, if you forget to handle the errors, you don't handle them at all" on one side. And "with exceptions, you do't necessarily have the immediate feedback that one may come" vs "with error values, you need to choose between sticking them in an error value variable, or explicitly ignoring it" (and with Go's fondness for "you assign to a variable that is then never used? That's a compile error!" it essentially means "you either handle the error or you intentionally disregard it".
Either is fine, I think. But, don't mix both in the same codebase. And with exceptions, I would really like Common Lisp-style restartable errors, to get the flexibility I feel I have with error values.
I suppose they're two sides of the same coin. Both can be done well or poorly.
I do resent the idea that error values are automatically better or easier to understand, because I'm dealing with some poorly done error values now and wishing for traditional exception handling.