//
// File: List.h    Class and type definitions for the
// C++ dynamic memory allocation implementation of ADT list
//

#ifndef LIST_H
#define LIST_H

#include "El.h"

typedef struct Node * NodePtr;
struct Node {
   El      el;
   NodePtr next;
};

class List {
public:
// List constructor and destructor
   List ();
   -List ();

// Methods that manipulate list nodes
   void storeInfo(El);
   El retrieveInfo();
   El retrieveNextInfo();

// Methods that manipulate the list
   void insert(El);
   void insertAfter(El);
   void remove();

// Methods that traverse the list
   void toFirst();
   void advance();

// Methods that test for certain conditions
   bool atFirst();
   bool atEnd();
   bool listIsEmpty();
   bool listIsFull();
   bool curIsEmpty();

private:
   NodePtr head;  // pointer to head node
   NodePtr cur;   // pointer to current node
   NodePtr prev;  // pointer to previous node

   NodePtr makeNode(El);
   void    destroyNode(NodePtr p);
   void    nodeReferenceError();
};

#endif