AddDependentManifestsToIgnoreList adds the dependant manifest to doNotAffect if the referred manifest has tags.

BuildRegexFilter compiles a regex state machine from a regex expression.

CollectTagFilters collects all matching repos and collects the associated tag filters.

GetMatchingRepos get all repositories in current registry, that match the provided regular expression.

GetRepositoryAndTagRegex splits the strings that are in the form <repository>:<regex filter>.

GetUntaggedManifests gets all the manifests for the command to be executed on.

UpdateForManifestWithoutSubjectToDelete adds the manifest to candidatesToDelete if the manifest does not have subject, otherwise add it to doNotDelete.