/*
** $Id: stack.h 739 2008-02-09 00:58:20Z phf $
**
** Interface for a simple stack of integers. Note that
** we don't have error returns in the interface, we do
** assume the client makes all the necessary checks.
**
** Note how we document what is *required* for the call
** to succeed, this is also called a "precondition".
*/

#ifndef _STACK_H
#define _STACK_H

/*
** Push a new integer on top of the stack.
** Requires: size() < capacity()
*/
void push(int);

/*
** Pop the top integer off the stack.
** Requires: size() > 0
*/
void pop(void);

/*
** Return the top integer on the stack.
** Requires: size() > 0
*/
int top(void);

/*
** Return the number of integers on the stack.
*/
int size(void);

/*
** Return the maximum size of the stack.
*/
int capacity(void);

#endif /* _STACK_H */