#ifndef DIFFERENTIATORNODES
#define DIFFERENTIATORNODES

#include <iostream>
#include <string>
#include "node.h"
#include "binaryNode.h"
#include "unaryNode.h"
#include "bFuncNode.h"

/**
 *A Node represents any item which can be part of an expression.
 *This includes constants, and binary operators. Node is a abstract base
 *class, while both constant and binary operators are subclasses.The binary
 *operators will become internal nodes, as will the unary operators,
 *while the constants will be external nodes.
 *
 * Written by Jessica Smith from code created by rcd.
 */



/**
 *The key class is a subclass of node which allows constants to be
 *created as nodes
 */
class Key : public Node
{
  public:
     /**
     *Makes a key node from the given value
     */
    Key (string key);
   
    /**
     *Virtual destructor for key
     */
    virtual ~Key();
    /**
     *Evaluates value of the key node
     */
    virtual double evaluate () const;
    /**
     *Prints out the value of the constant node
     */
    virtual void print (ostream & out) const;
    /**
     *Copies the node
     */
    virtual Node * copy () const;
    /**
     *Returns the precedebce of the node
     */
    virtual int precedence()const;
    /*
     *Returns the value of the int in string form
     */
     virtual string description()const;//returns double value
   
  private:
    string myKey;
     int myPrecedence;
    double myValue;
   
  
};
#endif