Ranges

This crate contains a performance-optimized type for generic version ranges and operations on them.

Ranges can represent version selectors such as (>=1.5.1, <2) OR (==3.1) OR (>4). Internally, it is an ordered list of contiguous intervals (segments) with inclusive, exclusive or open-ended ends, similar to a Vec<(Bound<T>, Bound<T>)>.

You can construct a basic range from one of the following build blocks. All other ranges are concatenation, union, and complement of these basic ranges.

• Ranges::empty(): No version
• Ranges::full(): All versions
• Ranges::singleton(v): Only the version v exactly
• Ranges::higher_than(v): All versions v <= versions
• Ranges::strictly_higher_than(v): All versions v < versions
• Ranges::lower_than(v): All versions versions <= v
• Ranges::strictly_lower_than(v): All versions versions < v
• Ranges::between(v1, v2): All versions v1 <= versions < v2

The optimized operations include complement, contains, contains_many, intersection, is_disjoint, subset_of and union.

Ranges is generic over any type that implements Ord + Clone and can represent all kinds of slices with ordered coordinates, not just version ranges. While built as a performance-critical piece of pubgrub, it can be adopted for other domains, too.

You can imagine a Ranges as slices over a number line.

Note that there are limitations to the equality implementation: Given a Ranges<u32>, the segments (Unbounded, Included(42u32)) and (Included(0), Included(42u32)) as well as (Included(1), Included(5)) and (Included(1), Included(3)) + (Included(4), Included(5)) are reported as unequal, even though the match the same versions: We can't tell that there isn't a version between 0 and -inf or 3 and 4 respectively.

Optional features

• serde: serialization and deserialization for the version range, given that the version type also supports it.
• proptest: Exports are proptest strategy for Ranges<u32>.