rust-ape-example/src/bin/error_iter_result.rs

// ./src/error/iter_result.md


fn part0() {
    let strings = vec!["tofu", "93", "18"];
    let numbers: Vec<_> = strings
        .into_iter()
        .map(|s| s.parse::<i32>())
        .collect();
    println!("Results: {:?}", numbers);
}

fn part1() {
    let strings = vec!["tofu", "93", "18"];
    let numbers: Vec<_> = strings
        .into_iter()
        .filter_map(|s| s.parse::<i32>().ok())
        .collect();
    println!("Results: {:?}", numbers);
}

fn part2() {
    let strings = vec!["42", "tofu", "93", "999", "18"];
    let mut errors = vec![];
    let numbers: Vec<_> = strings
        .into_iter()
        .map(|s| s.parse::<u8>())
        .filter_map(|r| r.map_err(|e| errors.push(e)).ok())
        .collect();
    println!("Numbers: {:?}", numbers);
    println!("Errors: {:?}", errors);
}

fn part3() {
    let strings = vec!["tofu", "93", "18"];
    let numbers: Result<Vec<_>, _> = strings
        .into_iter()
        .map(|s| s.parse::<i32>())
        .collect();
    println!("Results: {:?}", numbers);
}

fn part4() {
    let strings = vec!["tofu", "93", "18"];
    let (numbers, errors): (Vec<_>, Vec<_>) = strings
        .into_iter()
        .map(|s| s.parse::<i32>())
        .partition(Result::is_ok);
    println!("Numbers: {:?}", numbers);
    println!("Errors: {:?}", errors);
}

fn part5() {
    let strings = vec!["tofu", "93", "18"];
    let (numbers, errors): (Vec<_>, Vec<_>) = strings
        .into_iter()
        .map(|s| s.parse::<i32>())
        .partition(Result::is_ok);
    let numbers: Vec<_> = numbers.into_iter().map(Result::unwrap).collect();
    let errors: Vec<_> = errors.into_iter().map(Result::unwrap_err).collect();
    println!("Numbers: {:?}", numbers);
    println!("Errors: {:?}", errors);
}

pub fn main() {
	part0();
	part1();
	part2();
	part3();
	part4();
	part5();
}