GetFact looks up a single fact from the facts file, errors reading the file is reported but an absent fact is handled as empty result and no error.

GetFactJSON looks up a single fact from the JSON data, absent fact is handled as empty result and no error.

HasFact evaluates the expression against facts in the file.

JSON parses the data, including doing any conversions needed, and returns JSON text.

MatchFacts match fact filters in a OR manner, only facts matching all filters will be true.

MatchFile match fact filters in a OR manner, only nodes that have all the matching facts will be true here.

Logger provides logging facilities.