/*--------------------------------------------------------------------*/
/* stack.h                                                            */
/* Author: Bob Dondero                                                */
/* A generic Stack ADT interface                                      */
/*--------------------------------------------------------------------*/

#ifndef STACK_INCLUDED
#define STACK_INCLUDED

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

/* Return a new Stack_T object, or NULL is insufficient memory is
   available. */
Stack_T Stack_new(void);

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

/* Push pvItem onto oStack.  Return 1 (TRUE) if successful, or 0
   (FALSE) if insufficient memory is available. */
int Stack_push(Stack_T oStack, const void *pvItem);

/* Return the top item of oStack. */
void *Stack_top(Stack_T oStack);

/* Pop and discard the top item of oStack. */
void Stack_pop(Stack_T oStack);

/* Return 1 (TRUE) if oStack is empty, or 0 (FALSE) otherwise. */
int Stack_isEmpty(Stack_T oStack);

#endif