Functional example that demonstrates query with constraints.
It uses books.txt file to create objects with specified "name=value" properties, and then evaluate if object matches given constraints.
Example: "(Language == French OR Language == Spanish) AND BookNumber > 200" Will select all books in French or Spanish with BookNumber greater then 200.
"Genre == Detective AND (Language == Belgian OR Language == French)" Will select all Detective books in Belgian or French.
Check test.sh for more examples.