summaryrefslogtreecommitdiffstats
path: root/third_party/rust/semver/src/impls.rs
blob: c3b6c60133771fc742b5315f093ea4c68fbac2a6 (plain)
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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
use crate::backport::*;
use crate::identifier::Identifier;
use crate::{BuildMetadata, Comparator, Prerelease, VersionReq};
use core::cmp::Ordering;
use core::hash::{Hash, Hasher};
use core::iter::FromIterator;
use core::ops::Deref;

impl Default for Identifier {
    fn default() -> Self {
        Identifier::empty()
    }
}

impl Eq for Identifier {}

impl Hash for Identifier {
    fn hash<H: Hasher>(&self, hasher: &mut H) {
        self.as_str().hash(hasher);
    }
}

impl Deref for Prerelease {
    type Target = str;

    fn deref(&self) -> &Self::Target {
        self.identifier.as_str()
    }
}

impl Deref for BuildMetadata {
    type Target = str;

    fn deref(&self) -> &Self::Target {
        self.identifier.as_str()
    }
}

impl PartialOrd for Prerelease {
    fn partial_cmp(&self, rhs: &Self) -> Option<Ordering> {
        Some(Ord::cmp(self, rhs))
    }
}

impl PartialOrd for BuildMetadata {
    fn partial_cmp(&self, rhs: &Self) -> Option<Ordering> {
        Some(Ord::cmp(self, rhs))
    }
}

impl Ord for Prerelease {
    fn cmp(&self, rhs: &Self) -> Ordering {
        match self.is_empty() {
            true if rhs.is_empty() => return Ordering::Equal,
            // A real release compares greater than prerelease.
            true => return Ordering::Greater,
            // Prerelease compares less than the real release.
            false if rhs.is_empty() => return Ordering::Less,
            false => {}
        }

        let lhs = self.as_str().split('.');
        let mut rhs = rhs.as_str().split('.');

        for lhs in lhs {
            let rhs = match rhs.next() {
                // Spec: "A larger set of pre-release fields has a higher
                // precedence than a smaller set, if all of the preceding
                // identifiers are equal."
                None => return Ordering::Greater,
                Some(rhs) => rhs,
            };

            let string_cmp = || Ord::cmp(lhs, rhs);
            let is_ascii_digit = |b: u8| b.is_ascii_digit();
            let ordering = match (
                lhs.bytes().all(is_ascii_digit),
                rhs.bytes().all(is_ascii_digit),
            ) {
                // Respect numeric ordering, for example 99 < 100. Spec says:
                // "Identifiers consisting of only digits are compared
                // numerically."
                (true, true) => Ord::cmp(&lhs.len(), &rhs.len()).then_with(string_cmp),
                // Spec: "Numeric identifiers always have lower precedence than
                // non-numeric identifiers."
                (true, false) => return Ordering::Less,
                (false, true) => return Ordering::Greater,
                // Spec: "Identifiers with letters or hyphens are compared
                // lexically in ASCII sort order."
                (false, false) => string_cmp(),
            };

            if ordering != Ordering::Equal {
                return ordering;
            }
        }

        if rhs.next().is_none() {
            Ordering::Equal
        } else {
            Ordering::Less
        }
    }
}

impl Ord for BuildMetadata {
    fn cmp(&self, rhs: &Self) -> Ordering {
        let lhs = self.as_str().split('.');
        let mut rhs = rhs.as_str().split('.');

        for lhs in lhs {
            let rhs = match rhs.next() {
                None => return Ordering::Greater,
                Some(rhs) => rhs,
            };

            let is_ascii_digit = |b: u8| b.is_ascii_digit();
            let ordering = match (
                lhs.bytes().all(is_ascii_digit),
                rhs.bytes().all(is_ascii_digit),
            ) {
                (true, true) => {
                    // 0 < 00 < 1 < 01 < 001 < 2 < 02 < 002 < 10
                    let lhval = lhs.trim_start_matches('0');
                    let rhval = rhs.trim_start_matches('0');
                    Ord::cmp(&lhval.len(), &rhval.len())
                        .then_with(|| Ord::cmp(lhval, rhval))
                        .then_with(|| Ord::cmp(&lhs.len(), &rhs.len()))
                }
                (true, false) => return Ordering::Less,
                (false, true) => return Ordering::Greater,
                (false, false) => Ord::cmp(lhs, rhs),
            };

            if ordering != Ordering::Equal {
                return ordering;
            }
        }

        if rhs.next().is_none() {
            Ordering::Equal
        } else {
            Ordering::Less
        }
    }
}

impl FromIterator<Comparator> for VersionReq {
    fn from_iter<I>(iter: I) -> Self
    where
        I: IntoIterator<Item = Comparator>,
    {
        let comparators = Vec::from_iter(iter);
        VersionReq { comparators }
    }
}