Added support for Imply expression.

include/plasp/pddl/Expression.h

@@ -37,6 +37,9 @@ using Constants = std::vector<ConstantPointer>;
 class Either;
 using EitherPointer = std::unique_ptr<Either>;
 
+class Imply;
+using ImplyPointer = std::unique_ptr<Imply>;
+
 class Not;
 using NotPointer = std::unique_ptr<Not>;
 

include/plasp/pddl/expressions/Binary.h

@@ -0,0 +1,54 @@
+#ifndef __PLASP__PDDL__EXPRESSIONS__BINARY_H
+#define __PLASP__PDDL__EXPRESSIONS__BINARY_H
+
+#include <plasp/pddl/ConsistencyException.h>
+#include <plasp/pddl/Context.h>
+#include <plasp/pddl/Expression.h>
+#include <plasp/pddl/expressions/Variable.h>
+
+namespace plasp
+{
+namespace pddl
+{
+namespace expressions
+{
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// Binary
+//
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+class Binary: public Expression
+{
+	public:
+		const Expression *leftArgument() const;
+		const Expression *rightArgument() const;
+
+	protected:
+		template<typename ExpressionParser>
+		void parse(Context &context, const Variables &parameters, ExpressionParser parseExpression);
+
+	private:
+		ExpressionPointer m_leftArgument;
+		ExpressionPointer m_rightArgument;
+};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+template<typename ExpressionParser>
+void Binary::parse(Context &context, const Variables &parameters, ExpressionParser parseExpression)
+{
+	// Assume that expression identifier (imply, exists, etc.) is already parsed
+	// Parse arguments of the expression
+	m_leftArgument = parseExpression(context, parameters);
+	m_rightArgument = parseExpression(context, parameters);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+}
+}
+}
+
+#endif

include/plasp/pddl/expressions/Imply.h

@@ -0,0 +1,52 @@
+#ifndef __PLASP__PDDL__EXPRESSIONS__IMPLY_H
+#define __PLASP__PDDL__EXPRESSIONS__IMPLY_H
+
+#include <plasp/pddl/expressions/Binary.h>
+
+namespace plasp
+{
+namespace pddl
+{
+namespace expressions
+{
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// Imply
+//
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+class Imply: public Binary
+{
+	public:
+		template<typename ExpressionParser>
+		static ImplyPointer parse(Context &context, const Variables &parameters,
+			ExpressionParser parseExpression);
+
+	public:
+		void accept(ExpressionVisitor &expressionVisitor) const override;
+
+	private:
+		Imply() = default;
+};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+template<typename ExpressionParser>
+ImplyPointer Imply::parse(Context &context, const Variables &parameters,
+	ExpressionParser parseExpression)
+{
+	auto expression = std::make_unique<Imply>(Imply());
+
+	expression->Binary::parse(context, parameters, parseExpression);
+
+	return expression;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+}
+}
+}
+
+#endif

src/plasp/pddl/Expression.cpp

@@ -3,6 +3,7 @@
 #include <plasp/pddl/Context.h>
 #include <plasp/pddl/Identifier.h>
 #include <plasp/pddl/expressions/And.h>
+#include <plasp/pddl/expressions/Imply.h>
 #include <plasp/pddl/expressions/Not.h>
 #include <plasp/pddl/expressions/Or.h>
 #include <plasp/pddl/expressions/Predicate.h>
@@ -93,8 +94,9 @@ ExpressionPointer parseExpressionContent(const std::string &expressionIdentifier
 		expression = expressions::Or::parse(context, parameters, parseExpression);
 	else if (expressionIdentifier == "not")
 		expression = expressions::Not::parse(context, parameters, parseExpression);
-	else if (expressionIdentifier == "imply"
+	else if (expressionIdentifier == "imply")
-		|| expressionIdentifier == "exists"
+		expression = expressions::Imply::parse(context, parameters, parseExpression);
+	else if (expressionIdentifier == "exists"
 		|| expressionIdentifier == "forall"
 		|| expressionIdentifier == "-"
 		|| expressionIdentifier == "="

src/plasp/pddl/expressions/Binary.cpp

@@ -0,0 +1,38 @@
+#include <plasp/pddl/expressions/Binary.h>
+
+#include <algorithm>
+
+#include <plasp/pddl/Context.h>
+#include <plasp/pddl/ExpressionVisitor.h>
+#include <plasp/pddl/Identifier.h>
+
+namespace plasp
+{
+namespace pddl
+{
+namespace expressions
+{
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// Binary
+//
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+const Expression *Binary::leftArgument() const
+{
+	return m_leftArgument.get();
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+const Expression *Binary::rightArgument() const
+{
+	return m_rightArgument.get();
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+}
+}
+}

src/plasp/pddl/expressions/Imply.cpp

@@ -0,0 +1,27 @@
+#include <plasp/pddl/expressions/Imply.h>
+
+#include <plasp/pddl/ExpressionVisitor.h>
+
+namespace plasp
+{
+namespace pddl
+{
+namespace expressions
+{
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// Imply
+//
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void Imply::accept(plasp::pddl::ExpressionVisitor &expressionVisitor) const
+{
+	expressionVisitor.visit(*this);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+}
+}
+}