diff options
| -rw-r--r-- | tvix/eval/src/builtins/versions.rs | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/tvix/eval/src/builtins/versions.rs b/tvix/eval/src/builtins/versions.rs index 33679ed4034b..ee75eeaeed3b 100644 --- a/tvix/eval/src/builtins/versions.rs +++ b/tvix/eval/src/builtins/versions.rs @@ -1,14 +1,50 @@ +use std::cmp::Ordering; use std::ops::RangeInclusive; /// Version strings can be broken up into Parts. /// One Part represents either a string of digits or characters. /// '.' and '_' represent deviders between parts and are not included in any part. -#[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Debug)] +#[derive(PartialEq, Eq, Clone, Debug)] pub enum VersionPart<'a> { Word(&'a str), Number(&'a str), } +impl PartialOrd for VersionPart<'_> { + fn partial_cmp(&self, other: &Self) -> Option<Ordering> { + Some(self.cmp(other)) + } +} + +impl Ord for VersionPart<'_> { + fn cmp(self: &Self, other: &Self) -> Ordering { + match (self, other) { + (VersionPart::Number(s1), VersionPart::Number(s2)) => { + // Note: C++ Nix uses `int`, but probably doesn't make a difference + // We trust that the splitting was done correctly and parsing will work + let n1: u64 = s1.parse().unwrap(); + let n2: u64 = s2.parse().unwrap(); + n1.cmp(&n2) + } + + // empty Word always looses + (VersionPart::Word(""), VersionPart::Number(_)) => Ordering::Less, + (VersionPart::Number(_), VersionPart::Word("")) => Ordering::Greater, + + // `pre` looses unless the other part is also a `pre` + (VersionPart::Word("pre"), VersionPart::Word("pre")) => Ordering::Equal, + (VersionPart::Word("pre"), _) => Ordering::Less, + (_, VersionPart::Word("pre")) => Ordering::Greater, + + // Number wins against Word + (VersionPart::Number(_), VersionPart::Word(_)) => Ordering::Greater, + (VersionPart::Word(_), VersionPart::Number(_)) => Ordering::Less, + + (VersionPart::Word(w1), VersionPart::Word(w2)) => w1.cmp(w2), + } + } +} + /// Type used to hold information about a VersionPart during creation enum InternalPart { Number { range: RangeInclusive<usize> }, |