Discussion on: Else Before If In Rust

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Ok, but why better it's than the pattern matching?

    let num = Some(4);

    match num {
        Some(x) if x < 5 => println!("less than five: {}", x),
        Some(x) => println!("{}", x),
        None => (),
    }

doc.rust-lang.org/book/ch18-03-pat...

So your example like this:

fn main() {
    let n = 11;
    let x = match n {
        10 => "unless case 1".to_string(),
        // Match several values
        11 => "unless case 2".to_string(),
        // Match an inclusive range
        _ => "normal case".to_string(),
    };

    println!("{}",x);
}

Yufan Lou • Apr 27 '20

The point is to promote the normal case to the top. In your code the normal case is at the bottom.

The merit of promoting the normal case to the top is it is more natural to read and write. It's a very subtle and subjective merit.

b0c1 • Apr 27 '20

Great, but disagree.
Usually, your "normal case" is the "fallback" method in the control statement, because the else statement is optional and not necessary.
Your normal case is unnatural, because:

you always expect a "normal" way
and when not run the normal way? you may need to check all condition
so you first need to skip the normal way and scroll down to all other condition

The try/catch "normal case" is different. In try/catch you will try to do something and if something wrong you create a fallback.

but this is only my opinion :D