1  /*
       2   * stack.h -- Definitions for stack functions for use by extensions.
       3   */
       4  
       5  /* 
       6   * Copyright (C) 2012, 2013 the Free Software Foundation, Inc.
       7   * 
       8   * This file is part of GAWK, the GNU implementation of the
       9   * AWK Programming Language.
      10   * 
      11   * GAWK is free software; you can redistribute it and/or modify
      12   * it under the terms of the GNU General Public License as published by
      13   * the Free Software Foundation; either version 3 of the License, or
      14   * (at your option) any later version.
      15   * 
      16   * GAWK is distributed in the hope that it will be useful,
      17   * but WITHOUT ANY WARRANTY; without even the implied warranty of
      18   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      19   * GNU General Public License for more details.
      20   * 
      21   * You should have received a copy of the GNU General Public License
      22   * along with this program; if not, write to the Free Software
      23   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
      24   */
      25  
      26  extern int stack_empty();	/* return true if stack is empty */
      27  extern void *stack_top();	/* return top object on the stack */
      28  extern void *stack_pop();	/* pop top object and return it */
      29  extern int stack_push(void *);	/* push an object onto the stack,
      30  				 * return 0 if failed, 1 if success 
      31  				 */