Predicate that checks if one set intersects with another

libwccl/ops/intersects.h

+#ifndef INTERSECTS_H
+#define INTERSECTS_H
+
+#include <boost/shared_ptr.hpp>
+
+#include <libcorpus2/tagset.h>
+
+#include <libwccl/values/strset.h>
+#include <libwccl/values/tset.h>
+#include <libwccl/values/bool.h>
+#include <libwccl/ops/setpredicate.h>
+#include <libwccl/ops/formatters.h>
+
+namespace Wccl {
+
+/**
+ * Class that realises a predicate checking if one set intersects with another
+ */
+template <class T>
+class Intersects : public SetPredicate<T>
+{
+public:
+	typedef typename SetPredicate<T>::SetFunctionPtr SetFunctionPtr;
+
+	Intersects(const SetFunctionPtr& set1_expr, const SetFunctionPtr& set2_expr)
+		: SetPredicate<T>(set1_expr, set2_expr)
+	{
+	}
+
+	virtual const std::string raw_operator_name() const {
+		return "inter";
+	}
+
+protected:
+
+	typedef typename SetPredicate<T>::BaseRetValPtr BaseRetValPtr;
+
+	/**
+	 * Take value of possible subset in question. If it is an empty set, return False.
+	 * Otherwise, take value of the set that is being compared to.
+	 * Return True if the possible subset is indeed a subset of the compared set,
+	 * otherwise return False.
+	 */
+	virtual BaseRetValPtr apply_internal(const SentenceContext& context) const {
+		boost::shared_ptr<T> set1 = this->set1_expr_->apply(context);
+		boost::shared_ptr<T> set2 = this->set2_expr_->apply(context);
+		if(set1->is_subset_of(*set2)) {
+			return Predicate::True->apply(context);
+		}
+		return Predicate::False->apply(context);
+	}
+
+};
+
+} /* end ns Wccl */
+
+
+#endif // INTERSECTS_H