While I was working on adding RHEL EUS support, I ran across some inconsistencies when attempting to use the grype/version.semanticVersion, and when digging deeper, it was apparent that most version structs in the package had similar issues:

• the operand ordering semantics were inconsistent; some comparators returned results in terms of v1 vs v2 and others did v2 vs v1. Eventually, based on the values of versionObj.Format, the underlying object structs, and the implementation within each Compare() function, the results were correct, but hard to reason which ordering was correct.
• each version object needs to invoke finalizeComparisonVersion within their Compare method, which can easily be overlooked. Ideally this should be a single choke point in this package where this is done since all of the underlying types are not exported.
• decisions are being driven off of the versionObj.Format field deep within each type during comparison even though its the underlying state of the rich data structure that really drives this. Since there was no single source of truth on this, different implementations would choose which truth to lean on when making decisions, which made checking which behaviors were right more difficult.

This lead to refactoring much of the grype/version package; here are the summary of changes:

• Removes the rich struct in favor of type asserting specific version.comparator implementations.
• Inverts the value of the comparator results within constraint expression processing; this allows comparators to clearly do a v1 vs v2 comparison (instead of needing to flip this).
• Migrates all finalizeComparisonVersion logic to be done only in version.Version.Compare() (not within each version object implementation).
• Removes most of the constraint implementations and uses the genericConstraint object (less code).
• All testing now uses versions.NewVersion(value, format) so that we are getting a sense of the objects behavior as seen by callers of this package.