/*------------------------------------------------------------------*/
/* stackao.h:  A Stack Abstract Object                              */
/*------------------------------------------------------------------*/

#ifndef STACKAO_INCLUDED
#define STACKAO_INCLUDED

void Stack_init(void);
/* Initialize the Stack. 
   It is a checked runtime error for the Stack to be initialized. */

void Stack_free(void);
/* Free the resources consumed by the Stack.
   It is a checked runtime error for the Stack to be uninitialized. */

void Stack_push(int iItem);
/* Push iItem onto the Stack. 
   It is a checked runtime error for the Stack to uninitialized or to
   be full. */

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

int Stack_isFull(void); 
/* Return 1 (TRUE) iff the Stack is full.
   It is a checked runtime error for the Stack to be uninitialized. */ 

#endif