1pub const fn num_to_hex_digit(x: u8) -> u8 {
2 match x {
3 0..=9 => b'0' + x,
4 10..=15 => b'a' + (x - 10),
5 _ => panic!("invalid hex number"),
6 }
7}
8
9pub const fn num_from_dec_digit(d: u8) -> u8 {
10 match d {
11 b'0'..=b'9' => d - b'0',
12 _ => panic!("invalid dec digit"),
13 }
14}