Use a generic Interval or Range class.

[seaneagan]

Instead of a custom VersionRange class, it would be nice to use a generic Interval or Range class. I have a version of Interval here that I'd like to publish as an interval package that could be used. The repo for this package could be kept under the the dart-lang github org.

Then VersionConstraint could have an interval property which returned an Interval<Version>. Then instead of Version implementing VersionConstraint, could have new VersionConstraint.exact(version) whose interval could use Interval.singleton underneath. Then any custom toString() or == would be on VersionConstraint subclasses, and not on the interval itself.

This would of course be a breaking change, but there probably aren't too many consumers of this package yet, just a really big one in pub :).

[seaneagan]

Published the interval package.

One wrinkle is that Interval doesn't handle the semantics of VersionRange.allows disallowing pre-releases at the top-end of the range, so that would need to be overridden still.

[nex3]

I don't think we'd get enough benefit from this to make the migration worth it, nor does it seem like the interval package is actively maintained anymore.