Comment by samus
> * "Invisible control flow", where you can't tell from the call site whether or not a call might throw (you need to check the signature, which is off in some other file, or perhaps visible in an IDE if you hover).
Never found this this to be a problem. It is really common to all implementations of exceptions, not just checked ones. And when you write code the compiler will yell at you. In monadic code,
Invisible control flow is common to all implementations of unchecked exceptions (Java, C#, C++, Python, Ruby, etc). It means that any code, anywhere, at any time, can throw an exception which may represent a recoverable error.
People are used to that, and one common strategy is to not worry too much about handling individual exceptions but to instead wrap a big `try` block around everything near the outer boundary of your code. It’s good enough for many purposes and yields a high initial development velocity, but is comparatively fragile.
With Languages like Rust, Go, and Swift, only unrecoverable errors trigger the panic mechanism. Every call site where a recoverable error may occur is identifiable — in Rust via Result, `unwrap()`, the `?` operator, etc, in Go via returned Err (though unlike Rust you can discard them silently), and in Swift via the `try` operator.
You can still develop quickly by just unwrapping every Result, but unlike languages with invisible control flow, you can easily audit the codebase and go back to harden every site where a recoverable error may occur — yielding a level of robustness which is difficult to achieve in languages with unchecked exceptions.