3 ms·

As klodolph says, there's no axis for fallibility because the language doesn't offer different choices of fallibility strategy. There's just one: exceptions. Y

As klodolph says, there's no axis for fallibility because the language doesn't offer different choices of fallibility strategy. There's just one: exceptions. You can catch exceptions. If an iterator throws, you can catch that by surrounding the for loop in a try catch block. Futures are sort of like Result types in that a Future can complete with either a value or an error. Exceptions inside asynchronous functions are automatically caught and wrapped into error futures, which then propagate out through the returned future object. When you await a future, if the future completes with an error, that then gets unwrapped back into a thrown exception.

steveklabnik 4y ago
> Futures are sort of like Result types in that a Future can complete with either a value or an error. Incidentally, for curious readers, the first version of the Future trait in Rust always returned a Result<T, E> from its poll method. The second version decided to instead return T directly, since T could be Result<T, E> too, making things a bit more general, but also leading to a tiny bit of type tetris. Doesn't mean that I'm saying anything about whatever Dart does here, just that I also think there's a connection here :)