#include "jval.h"

typedef void *Queue;

extern Queue new_queue(); /* allocates an empty queue. */
extern void queue_enqueue(Queue q, Jval jv); /* puts a new piece of data, which
						is the Jval jv, into the 
						queue. */

extern Jval queue_dequeue(Queue q); /* returns the first item in the queue, and
				       at the same time removes that object 
				       from the queue. */

extern int queue_empty(Queue q); /* returns 1 if the queue is empty; 
				    0 otherwise */

extern int queue_size(Queue q); /* returns the number of elements in the 
				   queue */