/*------------------------------------------------------------------*/
/* stackadt.h:  A Stack ADT                                         */
/*------------------------------------------------------------------*/

#ifndef STACKADT_INCLUDED
#define STACKADT_INCLUDED

typedef struct Stack *Stack_T;
/* A Stack is a last-in-first-out collection of integers. */

Stack_T Stack_new(void);
/* Return a new Stack_T. */

void Stack_free(Stack_T oStack);
/* Free oStack. */

void Stack_push(Stack_T oStack, int iItem);
/* Push iItem onto oStack. 
   It is a checked runtime error for oStack to be NULL or full. */

int Stack_pop(Stack_T oStack);
/* Pop oStack, and return the popped item.
   It is a checked runtime error for oStack to be NULL or empty. */
 
int Stack_isEmpty(Stack_T oStack); 
/* Return 1 (TRUE) iff oStack is empty. 
   It is a checked runtime error for oStack to be NULL. */

int Stack_isFull(Stack_T oStack); 
/* Return 1 (TRUE) iff oStack is empty. 
   It is a checked runtime error for oStack to be NULL. */

#endif