I want to implement an AST for the following grammar:

and_expr : atom ((MULT^)? atom)*;

I have alraedy defined a MULTNode class as follow:

#define INC_MULTNode_hpp__

#include "BinaryOperatorAST.hpp"

/** A simple node to represent MULT operation */
class MULTNode : public BinaryOperatorAST {
public:
MULTNode(ANTLR_USE_NAMESPACE(antlr)RefCount
oken> token) : BinaryOperatorAST(token)
{
}

int value() const
{
return left()->value() * right()->value();
}

ANTLR_USE_NAMESPACE(std)string toString() const
{
return " *";
}

void initialize(int t, const ANTLR_USE_NAMESPACE(std)string& txt)
{
CalcAST::initialize(t, txt);
}
void initialize(ANTLR_USE_NAMESPACE(antlr)RefAST t)
{
CalcAST::initialize(t);
}
void initialize(ANTLR_USE_NAMESPACE(antlr)RefToken tok)
{
CalcAST::initialize(tok);
}
};

typedef ANTLR_USE_NAMESPACE(antlr)ASTRefCount RefMULTNode;

#endif //INC_MULTNode_hpp__


Please, let me know the approach.