Show Table of Contents
13.26. The Conditional Element Collect
The Conditional Element
collect allows rules to reason over a collection of objects obtained from the given source or from the working memory. In First Oder Logic terms this is the cardinality quantifier.
The result pattern of
collect can be any concrete class that implements the java.util.Collection interface and provides a default no-arg public constructor. You can use Java collections like ArrayList, LinkedList and HashSet or your own class, as long as it implements the java.util.Collection interface and provide a default no-arg public constructor.
Variables bound before the
collect CE are in the scope of both source and result patterns and therefore you can use them to constrain both your source and result patterns. Any binding made inside collect is not available for use outside of it.
Where did the comment section go?
Red Hat's documentation publication system recently went through an upgrade to enable speedier, more mobile-friendly content. We decided to re-evaluate our commenting platform to ensure that it meets your expectations and serves as an optimal feedback mechanism. During this redesign, we invite your input on providing feedback on Red Hat documentation via the discussion platform.