But only the first time. Once you add `throws FooException` to the caller signature, the compiler won't complain about any future callees that also happen to throw FooException, even if you did care about handling their exceptions yourself. With callees that return Result you do get to make that decision for every callee.
I would say "adding Result to the caller signature" provides a similar cascade, but it's not entirely true: Every call must separately be unwrapped. So consistently wrapping your Result calls with the '?' operator is similar to a gigantic try-catch block or adding 'throws CheckedException' everywhere.
So both the '?' operator and adding 'throws CheckedException' everywhere let you accidentally neglect proper error handling: You have a default that is syntactically almost invisible and frees you from thinking. The checked exceptions give you a little more freedom from thinking than the '?' operator.
No. You're choosing to write the `?` there to bubble up the error. It's a compiler error if you forget it. Whereas with `throws FooException` you only get forced to remember it the first time, and after that you're allowed to forget it.
...but you're not choosing to write the `throws FooException`?
I can only say that if the `?` weren't around and you had to write more verbose handling each time, having the question "How should this one particular error be handled?" might come up more often and might prevent more bugs than when you can carelessly `?`-annotate your way through a dozen lines without any equivalents of `finally { ... }` anywhere.
Now read the rest of the comment after where you stopped reading. Or reread https://news.ycombinator.com/item?id=42249525 I'm tired of repeating myself.