rust_support 0.1.2

A collection of utilities for Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44

use anyhow::*;

pub fn collect_results<T>(results: Vec<Result<T, anyhow::Error>>) -> Result<Vec<T>> {
    let (oks, errs) = split_results(results);

    if errs.is_empty() {
        Ok(oks)
    } else {
        Err(combined_err(errs))
    }
}

fn split_results<T>(results: Vec<Result<T, anyhow::Error>>) -> (Vec<T>, Vec<anyhow::Error>) {
    let (oks, errs): (Vec<_>, Vec<_>) = results.into_iter().partition(Result::is_ok);
    let oks = oks.into_iter().filter_map(Result::ok).collect();
    let errs = errs.into_iter().filter_map(Result::err).collect();

    (oks, errs)
}

fn combined_err(errs: Vec<anyhow::Error>) -> anyhow::Error {
    let len = errs.len();

    errs.into_iter()
        .map(|e| format!("{:#}", e))
        .fold(anyhow::anyhow!("{len} error(s) occurred"), |acc, e| {
            acc.context(e)
        })
}

#[test]
fn test_collect_results() {
    let results = vec![
        Ok(1),
        Err(anyhow::anyhow!("error 1")),
        Ok(2),
        Err(anyhow::anyhow!("error 2")),
    ];
    let result = collect_results(results);
    assert!(result.is_err());

    let formatted_error = format!("{:#}", result.unwrap_err());
    assert_eq!(formatted_error, "error 2: error 1: 2 error(s) occurred");
}