Rust: here is an array of strings, we are going to parse the array to numbers. If that conversion fails we handle the exception and return the minimum integer value. We then save the result in a new vector. We also print it.
I like rust, but I hate the example too. It’s needlessly complex. Should have just been a.unwrap_or(b).
The example even used unwrap_or_else where they should use unwrap_or. Then it uses std::i64::MIN as fallback value where they could use something like 0 that would be a better example and honestly make more sense there.
let parsed_numbers = ["1", "not a number", "3"]
.iter()
.map(|n| n.parse().unwrap_or(0))
.collect();
// prints "[1, 0, 3]"println!("{:?}", parsed_numbers);
Even without trimming this to something less convoluted, the same functionality (with different fallback value) could be written in more readable form.
Obviously in the context of the page something like this would make way more sense:
The Option type would have been a better example, and make it slightly less complicated.
Option is an enum with two variants; None and Some(T). You can chain Options with operations, describing a Monad chain, which is kind of what this meme represent.
There’s a nice list of this feature by language on the Wikipedia page for anyone interested: https://en.wikipedia.org/wiki/Null_coalescing_operator#Examples_by_languages
This was my first time actually seeing a Rust example, and I hate it.
Other languages: if a is null return b.
Rust: here is an array of strings, we are going to parse the array to numbers. If that conversion fails we handle the exception and return the minimum integer value. We then save the result in a new vector. We also print it.
I like rust, but I hate the example too. It’s needlessly complex. Should have just been a.unwrap_or(b).
The example even used unwrap_or_else where they should use unwrap_or. Then it uses
std::i64::MINas fallback value where they could use something like0that would be a better example and honestly make more sense there.let parsed_numbers = ["1", "not a number", "3"] .iter() .map(|n| n.parse().unwrap_or(0)) .collect(); // prints "[1, 0, 3]" println!("{:?}", parsed_numbers);Even without trimming this to something less convoluted, the same functionality (with different fallback value) could be written in more readable form.
Obviously in the context of the page something like this would make way more sense:
maybe_number.unwrap_or(0)Or perhaps more idiomatic version of the above:
maybe_number.unwrap_or_default()I think you could even get rid of the
iter()and thecollect()since it’s a small fixed size array.The Option type would have been a better example, and make it slightly less complicated.
Option is an enum with two variants; None and Some(T). You can chain Options with operations, describing a Monad chain, which is kind of what this meme represent.