/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "glk/alan2/types.h"
#include "glk/alan2/main.h"
#include "glk/alan2/stack.h"

namespace Glk {
namespace Alan2 {

/* PRIVATE DATA */

#define STACKSIZE 100

/* The AMACHINE STACK */
static Aptr stack[STACKSIZE];
static int stackp = 0;


#ifdef _PROTOTYPES_
void push(Aptr i)
#else
void push(i)
     Aptr i;
#endif
{
  if (stackp == STACKSIZE)
    syserr("Out of stack space.");
  stack[stackp++] = i;
}


#ifdef _PROTOTYPES_
Aptr pop(void)
#else
Aptr pop()
#endif
{
  if (stackp == 0)
    syserr("Stack underflow.");
  return(stack[--stackp]);
}


#ifdef _PROTOTYPES_
Aptr top(void)
#else
Aptr top()
#endif
{
  return(stack[stackp-1]);
}

} // End of namespace Alan2
} // End of namespace Glk