Why I Prefer Exceptions to Error Values
Why I Prefer Exceptions to Error Values
Exceptions are often a better way to handle errors than returning them as values. We argue that traditional exceptions provide better user and developer experience, and show that they even result in faster execution.
You're viewing a single thread.
The more I read about these kind of article the more I am amazed that our digital future is at hand in utterly incompetent people.
This person clearly have no understanding of monadic error (AKA Maybe/option monad or slightly more advanced Either monad), which is the first monad we teach at a class targeting second year undergrad.
The performance comparison is just plain factual error. The functional error code will continue to compute
n2when computation ofn1failed; the same do not happen in the exception version. If you compare codes with completely different traces, of course they will have different performance...A properly implemented monadic error will return as soon as compute for
n1failed, and never execute the rest of the code. This is the default and idiomatic behavior in Haskell, OCaml, F#, and rust. This performance problem doesn't even happen in LINQ-style handling like in C# and Kotlin (maybe also Typescript?).The point of monadic error is that its control flow is local, whereas exception is non-local. Specifically, the exception can be handled and occur anywhere in the code base, with no indication on the type level. So programmers will be constantly worrying about whether the exception in a function call is properly handled.
Even worse, when you try to catch a certain error, there is always the risk to accidentally catch similar exceptions in a library call or someone else's code. Writing good code with try-catch requires a lot of principle and style guides. But unlike monads, these principle and rules cannot be enforced by the type system, adding extra burden to programmers.
In fact, we have known for a long time that non-local control flows (goto, break, contiune, exception, long jump) are the breeding ground for spaghetti code. As an evidence, many non-local control flows (goto, long jump) are baned in most languages.
That being said, there are certainly cases, with proper documentation, that exception style is easy to write and understand. But I think they are very specific scenarios, which have to be justified on a case-by-case basis.
I think the author of the article just haven't understood how to use the ? operator yet, and don't think they deserve being called "utterly incompetent" for it. Whether something is a monad or not is not necessarily something a programmer should have to think about on a daily basis IMO.
I just think of rust errors as a tagged enum with either a value or an error. And the ? operator as syntax sugar for returning if something was an error. IMO that simple understanding is sufficient to do error handling in Rust. I don't think we should gatekeep programming behind some intellectual barrier of whether or not you understand category theory. I certainly don't understand what a monad is, but I can still write working software and do error handling without unwraps.
I was making a shared library at work and was recently asked to start throwing exceptions, because the users wouldn't care to check my returned error and just continue with the empty returned data.
Well, now they will most probably have an empty catch block and continue doing what they did before.Nothing can fix a lazy worker.