adding AssignmentExpression

inc/AST/AssignmentExpression.h

@@ -0,0 +1,22 @@
+#ifndef ASSIGNMENTEXPRESSION_H
+#define ASSIGNMENTEXPRESSION_H
+
+#include "AST/Expression.h"
+#include <string>
+
+class AssignmentExpression : public Expression
+{
+public:
+    AssignmentExpression(std::string id, Expression* expr);
+    virtual ~AssignmentExpression();
+
+    virtual void accept(ASTVisitor *visitor);
+
+    std::string getId();
+    Expression* getExpr();
+private:
+        std::string id_;
+        Expression* expr_;
+};
+
+#endif // ASSIGNMENTEXPRESSION_H