str-utils 0.3.1

This crate provides some traits to extend `[u8]`, `str` and `Cow<str>`.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105

/// To extend `[u8]` and `str` to have `starts_with_ignore_ascii_case`, `starts_with_ignore_ascii_case_with_lowercase` and `starts_with_ignore_ascii_case_with_uppercase` methods.
pub trait StartsWithIgnoreAsciiCase {
    /// Returns `true` if the given string slice case-insensitively (only ignoring ASCII case) matches a prefix of this string slice.
    fn starts_with_ignore_ascii_case<S: AsRef<[u8]>>(&self, b: S) -> bool;

    /// Returns `true` if the given lowercase string slice case-insensitively (only ignoring ASCII case) matches a prefix of this string slice.
    fn starts_with_ignore_ascii_case_with_lowercase<S: AsRef<[u8]>>(&self, b: S) -> bool;

    /// Returns `true` if the given uppercase string slice case-insensitively (only ignoring ASCII case) matches a prefix of this string slice.
    fn starts_with_ignore_ascii_case_with_uppercase<S: AsRef<[u8]>>(&self, b: S) -> bool;
}

impl StartsWithIgnoreAsciiCase for [u8] {
    #[inline]
    fn starts_with_ignore_ascii_case<S: AsRef<[u8]>>(&self, b: S) -> bool {
        let b = b.as_ref();

        let b_length = b.len();

        if b_length == 0 {
            return true;
        }

        let a = self;

        let a_length = a.len();

        if a_length >= b_length {
            unsafe { a.get_unchecked(..b_length) }.eq_ignore_ascii_case(b)
        } else {
            false
        }
    }

    #[inline]
    fn starts_with_ignore_ascii_case_with_lowercase<S: AsRef<[u8]>>(&self, b: S) -> bool {
        let b = b.as_ref();

        debug_assert!(!b.iter().any(|e| e.is_ascii_uppercase()));

        let b_length = b.len();

        if b_length == 0 {
            return true;
        }

        let a = self;

        let a_length = a.len();

        if a_length >= b_length {
            !unsafe { a.get_unchecked(..b_length) }
                .iter()
                .map(|e| e.to_ascii_lowercase())
                .zip(b.iter().copied())
                .any(|(ac, bc)| ac != bc)
        } else {
            false
        }
    }

    #[inline]
    fn starts_with_ignore_ascii_case_with_uppercase<S: AsRef<[u8]>>(&self, b: S) -> bool {
        let b = b.as_ref();

        debug_assert!(!b.iter().any(|e| e.is_ascii_lowercase()));

        let b_length = b.len();

        if b_length == 0 {
            return true;
        }

        let a = self;

        let a_length = a.len();

        if a_length >= b_length {
            !unsafe { a.get_unchecked(..b_length) }
                .iter()
                .map(|e| e.to_ascii_uppercase())
                .zip(b.iter().copied())
                .any(|(ac, bc)| ac != bc)
        } else {
            false
        }
    }
}

impl StartsWithIgnoreAsciiCase for str {
    #[inline]
    fn starts_with_ignore_ascii_case<S: AsRef<[u8]>>(&self, b: S) -> bool {
        self.as_bytes().starts_with_ignore_ascii_case(b)
    }

    #[inline]
    fn starts_with_ignore_ascii_case_with_lowercase<S: AsRef<[u8]>>(&self, b: S) -> bool {
        self.as_bytes().starts_with_ignore_ascii_case_with_lowercase(b)
    }

    #[inline]
    fn starts_with_ignore_ascii_case_with_uppercase<S: AsRef<[u8]>>(&self, b: S) -> bool {
        self.as_bytes().starts_with_ignore_ascii_case_with_uppercase(b)
    }
}