syn/
whitespace.rs

1pub(crate) fn skip(mut s: &str) -> &str {
2    'skip: while !s.is_empty() {
3        let byte = s.as_bytes()[0];
4        if byte == b'/' {
5            if s.starts_with("//")
6                && (!s.starts_with("///") || s.starts_with("////"))
7                && !s.starts_with("//!")
8            {
9                if let Some(i) = s.find('\n') {
10                    s = &s[i + 1..];
11                    continue;
12                } else {
13                    return "";
14                }
15            } else if s.starts_with("/**/") {
16                s = &s[4..];
17                continue;
18            } else if s.starts_with("/*")
19                && (!s.starts_with("/**") || s.starts_with("/***"))
20                && !s.starts_with("/*!")
21            {
22                let mut depth = 0;
23                let bytes = s.as_bytes();
24                let mut i = 0;
25                let upper = bytes.len() - 1;
26                while i < upper {
27                    if bytes[i] == b'/' && bytes[i + 1] == b'*' {
28                        depth += 1;
29                        i += 1; // eat '*'
30                    } else if bytes[i] == b'*' && bytes[i + 1] == b'/' {
31                        depth -= 1;
32                        if depth == 0 {
33                            s = &s[i + 2..];
34                            continue 'skip;
35                        }
36                        i += 1; // eat '/'
37                    }
38                    i += 1;
39                }
40                return s;
41            }
42        }
43        match byte {
44            b' ' | 0x09..=0x0D => {
45                s = &s[1..];
46                continue;
47            }
48            b if b <= 0x7F => {}
49            _ => {
50                let ch = s.chars().next().unwrap();
51                if is_whitespace(ch) {
52                    s = &s[ch.len_utf8()..];
53                    continue;
54                }
55            }
56        }
57        return s;
58    }
59    s
60}
61
62fn is_whitespace(ch: char) -> bool {
63    // Rust treats left-to-right mark and right-to-left mark as whitespace
64    ch.is_whitespace() || ch == '\u{200e}' || ch == '\u{200f}'
65}
syn/whitespace.rs

syn/
whitespace.rs
