Function vec_alphabet

src/common/util.rs:12–18

n, item length n = 1, vec!["a", "b", ... "z"] n = 2, vec!["aa", "bb", ... "zz"]

(n: usize)

// n = 1, vec!["a", "b", ... "z"]
// n = 2, vec!["aa", "bb", ... "zz"]
pub fn vec_alphabet(n: usize) -> Vec<String> {
    debug_assert!(n > 0);
    "abcdefghijklmnopqrstuvwxyz"
        .chars()
        .map(|c| String::from(c).repeat(n))
        .collect()
}

/// return d-th character of s, -1 if d = length of string
#[inline(always)]