[jcranmer]

> What I'm getting at is that I'm a fan of the way Rust does error handling, but I don't get _why_ it feels different to the way Java does it.

It's because of the way the exception information gets annotated. In Rust, exception information is part of the return type, so you can handle potentially-exceptional functions using mechanisms that are generic over any return type. For example, Iterator::map lets you call every function that might fail, and gather the results as failures, even if you don't fail-fast. But in Java, the exception information is passed in a separate part of the type signature, so generic functions have to be written differently to also handle functions that might fail.