Class OptionalItemEvaluator

  • All Implemented Interfaces:

    public class OptionalItemEvaluator
    extends java.lang.Object
    implements SequenceEvaluator
    A SequenceEvaluator for expressions that return a sequence of zero or one items. Unlike the SingleItemEvaluator, it checks whether the underlying ItemEvaluator has returned null, and if so, returns an empty sequence rather than a single item.