memchr/
naive.rs

1#![allow(dead_code)]
2
3pub fn memchr(n1: u8, haystack: &[u8]) -> Option<usize> {
4    haystack
5        .iter()
6        .position(|&b| b == n1)
7}
8
9pub fn memchr2(n1: u8, n2: u8, haystack: &[u8]) -> Option<usize> {
10    haystack
11        .iter()
12        .position(|&b| b == n1 || b == n2)
13}
14
15pub fn memchr3(n1: u8, n2: u8, n3: u8, haystack: &[u8]) -> Option<usize> {
16    haystack
17        .iter()
18        .position(|&b| b == n1 || b == n2 || b == n3)
19}
20
21pub fn memrchr(n1: u8, haystack: &[u8]) -> Option<usize> {
22    haystack
23        .iter()
24        .rposition(|&b| b == n1)
25}
26
27pub fn memrchr2(n1: u8, n2: u8, haystack: &[u8]) -> Option<usize> {
28    haystack
29        .iter()
30        .rposition(|&b| b == n1 || b == n2)
31}
32
33pub fn memrchr3(n1: u8, n2: u8, n3: u8, haystack: &[u8]) -> Option<usize> {
34    haystack
35        .iter()
36        .rposition(|&b| b == n1 || b == n2 || b == n3)
37}