Added dummy expression to check that with removed double negations, expressions are still correctly normalized.

include/plasp/pddl/Expression.h

@@ -81,6 +81,7 @@ class Expression
 			At,
 			Binary,
 			Constant,
+			Dummy,
 			Either,
 			Imply,
 			Not,
@@ -89,7 +90,7 @@ class Expression
 			Predicate,
 			PrimitiveType,
 			Unsupported,
-			Variable
+			Variable,
 		};
 
 	public:

include/plasp/pddl/expressions/Dummy.h

@@ -0,0 +1,38 @@
+#ifndef __PLASP__PDDL__EXPRESSIONS__DUMMY_H
+#define __PLASP__PDDL__EXPRESSIONS__DUMMY_H
+
+#include <plasp/pddl/Expression.h>
+
+namespace plasp
+{
+namespace pddl
+{
+namespace expressions
+{
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// Dummy
+//
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+class Dummy: public ExpressionCRTP<Dummy>
+{
+	public:
+		static const Expression::Type ExpressionType = Expression::Type::Dummy;
+
+		bool isNormalized() const;
+
+		ExpressionPointer normalize() override;
+
+	private:
+		bool m_isNormalized = false;
+};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+}
+}
+}
+
+#endif

src/plasp/pddl/expressions/Dummy.cpp

@@ -0,0 +1,36 @@
+#include <plasp/pddl/expressions/Dummy.h>
+
+#include <plasp/pddl/IO.h>
+
+namespace plasp
+{
+namespace pddl
+{
+namespace expressions
+{
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// Dummy
+//
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+bool Dummy::isNormalized() const
+{
+	return m_isNormalized;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+ExpressionPointer Dummy::normalize()
+{
+	m_isNormalized = true;
+
+	return nullptr;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+}
+}
+}

tests/TestPDDLNormalization.cpp

@@ -1,7 +1,7 @@
 #include <gtest/gtest.h>
 
+#include <plasp/pddl/expressions/Dummy.h>
 #include <plasp/pddl/expressions/Not.h>
-#include <plasp/pddl/expressions/Unsupported.h>
 
 using namespace plasp::pddl;
 
@@ -11,13 +11,14 @@ TEST(PDDLNormalizationTests, DoubleNegation)
 {
 	auto n1 = std::make_unique<expressions::Not>();
 	auto n2 = std::make_unique<expressions::Not>();
-	auto u = std::make_unique<expressions::Unsupported>();
+	auto d = std::make_unique<expressions::Dummy>();
-	const auto up = u.get();
+	const auto dp = d.get();
 
-	n2->setArgument(std::move(u));
+	n2->setArgument(std::move(d));
 	n1->setArgument(std::move(n2));
 
 	auto normalized = n1->normalize();
 
-	ASSERT_EQ(normalized.get(), up);
+	ASSERT_EQ(normalized.get(), dp);
+	ASSERT_TRUE(dp->isNormalized());
 }