error.rs

pub fn challenge3() {
    let valid_chars: Vec<char> = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789,.- ".chars().collect();
    let repeated_char_score = 1;

    let mut input = String::new();

    println!("Single-byte XOR cipher");
    print!("encoded string> ");
    io::stdout().flush().unwrap();
    io::stdin().read_line(&mut input).expect("Failed to read line");

    // no line ending please!
    input.pop();

    let input_bytes = hex_decode(&input);
    let range = 0..255;
    let mut scores: Vec<(u8, i32, String)> = range.filter_map(|byte| {
        let text = byte_xor(&input_bytes, byte);
        if let Ok(text_str) = String::from_utf8(text) {
            let text_chars: Vec<char> = text_str.chars().collect();
            let text_score = score_text(&text_chars, &valid_chars, repeated_char_score);

            Some((byte, text_score, text_str))
        }
        else {
            None
        }
    }).collect();

    // sort by score
    scores.sort_by(|a, b| b.1.cmp(&a.1));

    println!("{} on byte {} from text '{}'", scores[0].1, scores[0].0, scores[0].2);
}

pub fn challenge4() {

    let valid_chars: Vec<char> = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789,.- ".chars().collect();
    let repeated_char_score = 1;

    let mut input = String::new();

    println!("Detect single-character XOR");
    print!("file path> ");
    io::stdout().flush().unwrap();
    io::stdin().read_line(&mut input).expect("Failed to read line");

    // no line ending please!
    input.pop();

    let file = BufReader::new(File::open(input).unwrap());
    
    let mut file_scores: Vec<(String, u8, i32, String)> = file.lines().map(|line| {
        let input_str: String = line.unwrap();
        let input_bytes = hex_decode(&input_str);
        let range = 0..255;
        let mut scores: Vec<(u8, i32, String)> = range.filter_map(|byte| {
            let text = byte_xor(&input_bytes, byte);
            if let Ok(text_str) = String::from_utf8(text) {
                let text_chars: Vec<char> = text_str.chars().collect();
                let text_score = score_text(&text_chars, &valid_chars, repeated_char_score);

                Some((byte, text_score, text_str))
            }
            else {
                None
            }
        }).collect();

        // sort by score
        scores.sort_by(|a, b| b.1.cmp(&a.1));

        // error here on `scores[0].2`
        (input_str, scores[0].0, scores[0].1, scores[0].2)
    }).collect();

    file_scores.sort_by(|a, b| b.2.cmp(&a.2));

    println!("{} on byte {} from text '{}' in string '{}'", file_scores[0].2, file_scores[0].1, file_scores[0].3, file_scores[0].0);
}