Comment by Akronymus
20 hours ago
> I think I get it but I'm not really sure what I'm gaining over exception types. With an intelligent use of exceptions I can easily specify the happy path and all the error paths separately which seems really nice to me, ...
Until your coworker comes along and accidentally refactors the code to skip the exception catching and it suddenly blows up prod.
With tagged unions you can't accidentally dereference to the underlying value without checking if it's actually proper data first.
> Until your coworker comes along and accidentally refactors the code to skip the exception catching and it suddenly blows up prod.
can't my co-worker just use this pattern and discard an error result the same? I'd argue its easier as the stack wont unwind by default because the error is returned instead of thrown.
Not quite, as the compiler wouldnt let let you use the "value" in that case. So if you discard the error path, you simply wont have any value to use further on in the code.