#ifndef _QUEUE_H
#define _QUEUE_H

#include "list.h"                  // queue relies on list to work
                                   // (which relies on node)
struct queue {
    List *data;                    // pointer to list containing data
    Node *front;                   // pointer to node at front of queue
    Node *back;                    // pointer to node at back of queue
    int   buffer;                  // maximum queue size (0 is unbounded)
};
typedef struct queue Queue;        // because we deserve nice things

Queue *mkqueue(int              ); // create new queue (of max size)
Queue *cpqueue(Queue *          ); // create a copy of an existing queue
Queue *rmqueue(Queue *          ); // clear and de-allocate an existing queue

Queue *purge(Queue *            ); // empty a given queue

int    enqueue(Queue **, Node * ); // add new node to the back of queue
int    dequeue(Queue **, Node **); // take off node at front of queue

#endif