I’ll be honest, when I was learning to program in Java I mostly just wrapped errors in an empty try catch to shut them up, with no regard for actually handling them.
Java requiring you to write every exception that can happen in your code isn’t helpful.
Explicit error types are great, but Java managed to make them on a way where you get almost none of the upside and is so full of downsides that indoctrinated a generation into thinking knowing your errors is bad.
I think the problem is that many introductory examples use unwrap, so many beginner programmers don’t get exposed to alternatives like unwrap_or and the likes.
Yeah, we onboarded some folks into a Rust project last year and a few months in, they were genuinely surprised when I told them that unwrapping is pretty bad. Granted, they probably did read about it at some point and just forgot, but that isn’t helped by lots of code using .unwrap() either.
Can’t resist pointing out how you should actually write the function in a “real” scenario (but still not handling errors properly), in case anyone wants to know.
If the list is guaranteed to have exactly two elements:
Even better to use expect with a short message of what the assumption is: “the string should contain a comma” if it ever panics you’ll know exactly why.
The weird part of rust is replacing straight forward semicolons from other languages with the more verbose
.unwrap();.Just kidding, don’t lecture me about it.
You can also use a shorter version .clone();
?But then someone will have to deal with it somewhere, better just unwrap it under the carpet.
Exactly
expr
The amount of people on the internet seriously complaining that both Rust error handling sucks and that
.unwrap();is too verbose is just staggering.I’ll be honest, when I was learning to program in Java I mostly just wrapped errors in an empty try catch to shut them up, with no regard for actually handling them.
I assume most other learners do that too.
Java requiring you to write every exception that can happen in your code isn’t helpful.
Explicit error types are great, but Java managed to make them on a way where you get almost none of the upside and is so full of downsides that indoctrinated a generation into thinking knowing your errors is bad.
I think the problem is that many introductory examples use
unwrap, so many beginner programmers don’t get exposed to alternatives likeunwrap_orand the likes.Yeah, we onboarded some folks into a Rust project last year and a few months in, they were genuinely surprised when I told them that unwrapping is pretty bad. Granted, they probably did read about it at some point and just forgot, but that isn’t helped by lots of code using
.unwrap()either.Me, every time I try searching a Rust question.
That’s easy. Just do:
fn is_second_num_positive() -> bool { let input = "123,-45"; let is_positive = input.split(',') .collect::<Vec<&str>>() .last() .unwrap() .parse::<i32>() .unwrap() .is_positive(); is_positive }Can’t resist pointing out how you should actually write the function in a “real” scenario (but still not handling errors properly), in case anyone wants to know.
If the list is guaranteed to have exactly two elements:
fn is_second_num_positive_exact(input: &str) -> bool { let (_, n) = input.split_once(',').unwrap(); n.parse::<i32>().unwrap() > 0 }If you want to test the last element:
fn is_last_num_positive(input: &str) -> bool { let n = input.split(',').next_back().unwrap(); n.parse::<i32>().unwrap() > 0 }If you want to test the 2nd (1-indexed) element:
fn is_second_num_positive(input: &str) -> bool { let n = input.split(',').nth(1).unwrap(); n.parse::<i32>().unwrap() > 0 }Even better to use
expectwith a short message of what the assumption is: “the string should contain a comma” if it ever panics you’ll know exactly why.Can still use
.is_positive(), though…