# Variables
Cache caches holdings information.
# Structs
AndFilter returns true, only if all filters return true.
AnyFilter validates any record.
CacheValue groups holdings and cache for fast lookups.
CollectionFilter returns true, if the record belongs to any one of the collections.
DOIFilter allows records with a given DOI.
HoldingsFilter compares a record to a kbart file.
ISBNFilter allows records with a certain ISBN.
ISSNFilter allows records with a certain ISSN.
NotFilter inverts another filter.
OrFilter returns true, if at least one filter matches.
PackageFilter allows all records of one of the given package name.
SourceFilter allows all records with the given source id or ids.
SubjectFilter returns true, if the record has an exact string match to one of the given subjects.
Tagger takes a list of labels (ISILs) and annotates an intermediate schema according to a number of filters, defined per labels The tagger is loaded directly from JSON.
Tree allows polymorphic filters.
# Interfaces
Filter returns go or no for a given record.
# Type aliases
HoldingsCache caches items keyed by filename or url.