kaira/
lib.rs

1pub fn is_key(input: &str) -> bool {
2    if input.as_bytes()[0usize] != b'-' {
3        return false;
4    }
5
6    if input.as_bytes()[1usize] != b'-' {
7        if input.len() != 2 {
8            return false;
9        }
10
11        return input.chars().nth(1).unwrap().is_alphabetic();
12    }
13
14    return input[2..].chars().all(|c| c.is_alphanumeric());
15}
16
17#[cfg(test)]
18mod tests {
19    use super::*;
20
21    #[test]
22    fn test_alphanumeric() {
23        let key = "--key";
24        assert_eq!(is_key(key), true);
25    }
26}