swc_css_minifier/compressor/
unicode_range.rs

1use swc_css_ast::*;
2
3use super::Compressor;
4
5impl Compressor {
6    pub(super) fn compress_unicode_range(&self, unicode_range: &mut UnicodeRange) {
7        unicode_range.start = unicode_range.start.to_ascii_lowercase();
8        if let Some(end) = &mut unicode_range.end {
9            *end = end.to_ascii_lowercase();
10        }
11
12        if unicode_range.end.is_none() {
13            unicode_range.start = self.remove_leading_zeros(&unicode_range.start).into();
14
15            return;
16        }
17
18        let start = &unicode_range.start;
19        let end = unicode_range.end.as_ref().unwrap();
20        let merged = self.merge_start_and_end(start, end);
21
22        if let Some(merged) = &merged {
23            unicode_range.start = self.remove_leading_zeros(merged).into();
24            unicode_range.end = None;
25        } else {
26            unicode_range.start = self.remove_leading_zeros(start).into();
27            unicode_range.end = Some(self.remove_leading_zeros(end).into());
28        }
29    }
30
31    fn remove_leading_zeros(&self, value: &str) -> String {
32        let mut result = String::with_capacity(value.len());
33        let mut is_leading = true;
34
35        for c in value.chars() {
36            if c == '0' && is_leading {
37                continue;
38            }
39
40            is_leading = false;
41
42            result.push(c);
43        }
44
45        result
46    }
47
48    fn merge_start_and_end(&self, start: &str, end: &str) -> Option<String> {
49        let mut minified = String::new();
50        let mut question_counter = 0;
51
52        for (idx, start_c) in start.chars().enumerate() {
53            if let Some(end_c) = &end.chars().nth(idx) {
54                if start_c == *end_c && question_counter == 0 {
55                    minified.push(start_c);
56                } else if start_c == '0' && *end_c == 'f' {
57                    question_counter += 1;
58
59                    minified.push('?')
60                } else {
61                    return None;
62                }
63            } else {
64                return None;
65            }
66        }
67
68        Some(minified)
69    }
70}
swc_css_minifier/compressor/unicode_range.rs

swc_css_minifier/compressor/
unicode_range.rs
