Distinguish between zero values and missing values

I have a need to distinguish between "2" and "2.0" post-parsing, without having to re-parse these strings.

For example, I am writing an automated system to identify when software component versions are no longer supported. The data about support timelines can vary about specificity, so that some products exit support as of a major-wide series 2.x ("2"), whereas other products develop at a much faster rate and can exit support as of particular minor versions ("2.0").

Unfortunately, it appears that semver simply defaults unspecified minor version values, etc. etc. as zero, without providing a clear way to distinguish between an explicit zero input, versus an implicit default of missing information to zero.

I think I may hack around this gap by counting the periods in the original version string prior to parsing with semver. But I would love for a standard feature such as HasMinor(), HasPatch(), HasBuild(), to clarify in a reliable way.

Start by reviewing the semver parsing API and how it represents omitted minor, patch, and build components. Define how callers can distinguish an explicit zero from a missing value, including the requested HasMinor(), HasPatch(), and HasBuild() behavior. Done means parsed versions reliably expose that distinction without requiring callers to re-parse the original string.