style/properties_and_values/syntax/
ascii.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5/// Trims ASCII whitespace characters from a slice, and returns the trimmed input.
6pub fn trim_ascii_whitespace(input: &str) -> &str {
7    if input.is_empty() {
8        return input;
9    }
10
11    let mut start = 0;
12    {
13        let mut iter = input.as_bytes().iter();
14        loop {
15            let byte = match iter.next() {
16                Some(b) => b,
17                None => return "",
18            };
19
20            if !byte.is_ascii_whitespace() {
21                break;
22            }
23            start += 1;
24        }
25    }
26
27    let mut end = input.len();
28    assert!(start < end);
29    {
30        let mut iter = input.as_bytes()[start..].iter().rev();
31        loop {
32            let byte = match iter.next() {
33                Some(b) => b,
34                None => {
35                    debug_assert!(false, "We should have caught this in the loop above!");
36                    return "";
37                },
38            };
39
40            if !byte.is_ascii_whitespace() {
41                break;
42            }
43            end -= 1;
44        }
45    }
46
47    &input[start..end]
48}
49
50#[test]
51fn trim_ascii_whitespace_test() {
52    fn test(i: &str, o: &str) {
53        assert_eq!(trim_ascii_whitespace(i), o)
54    }
55
56    test("", "");
57    test(" ", "");
58    test(" a b c ", "a b c");
59    test(" \t \t \ta b c \t \t \t \t", "a b c");
60}
style/properties_and_values/syntax/ascii.rs

style/properties_and_values/syntax/
ascii.rs
