/*	avl.h		Definitions for avl routines

	Copyright 1988 Zinn Computer Company
	by Mark E. Mallett
	All Rights Reserved

	This software may be used at will, provided that all credits
	and style be left in place, and that its distribution is not
	restricted. Bug fixes and improvements are welcomed, please
	send these back to me at mem@zinn.MV.COM
*/

#ifndef	H_AVL				/* Prevent multiple inclusions */
#define	H_AVL

	/*--------------------------------------------------------------
	 * rlp900624 -- Support for Lattice-style prototypes
	 *	If MSDOS, I assume Microsoft C compiler for DOS and OS/2
	 *	If Lattice, I assume Lattice C compiler for Amiga
	 *--------------------------------------------------------------
	 */

#ifndef __ARGS
 #if	defined(MSDOS) || defined(LATTICE)
  #define __ARGS(a) a
 #else
  #define __ARGS(a) ()
 #endif
#endif

#ifndef	TRUE				/* Same old jazz */
#define	TRUE	1
#define	FALSE	0
#endif	TRUE

#ifndef	NULL
#define	NULL	((char *)0)
#endif	NULL

#ifndef	NUL
#define	NUL	'\0'
#endif	NUL

	/*-------------------------------------------
	 * rlp900624 -- added typedefs and prototypes
	 *-------------------------------------------
	 */

	typedef	struct _AVLNODE	AVLNODE;
	typedef	struct _AVLTREE	AVLTREE;

	typedef	int	(*PFNCMPRTC)  __ARGS((void *, AVLNODE *));
	typedef	AVLNODE	*(*PFNMKNODE) __ARGS((AVLTREE *, void *, void *, AVLNODE *));
	typedef	int	(*PFNRMNODE)  __ARGS((AVLTREE *, AVLNODE *));

	AVLNODE	*avlfind  __ARGS(( AVLTREE *treeP, void *keyP ));
	int	avlinsert __ARGS(( AVLTREE *treeP, void *keyP, void *dataP ));
	int	avldelete __ARGS(( AVLTREE *treeP, void *keyP ));

	/* Structures */

/* Structure of an avl tree node.  Note that this node is meant to
   be used as a header or component of an application-specific structure,
   since there is no key or data information present in the avlnode
   structure.
*/

typedef					/* A node in an AVL tree */
  struct _AVLNODE {
    AVLNODE	*n_leftP;		/* Ptr to left subtree */
    AVLNODE	*n_rightP;		/* Ptr to right subtree */
    int		n_balance;		/* Balance count */
  } AVLNODE;

typedef					/* The header for an AVL tree */
  struct _AVLTREE {
    /* Tree parameters */
    AVLNODE	*t_rootP;		/* Ptr to root node */

    /* Handler functions for the tree */
    /* rlp900622 -- use my typedefs for these function ptrs */

    PFNCMPRTC t_cmprtc;	    /* int	(*t_cmprtc)();  Compare two keys */
    PFNMKNODE t_mknode;	    /* AVLNODE *(*t_mknode)();  Node maker       */
    PFNRMNODE t_rmnode;	    /* int	(*t_rmnode)();  Node destroyer   */
  } AVLTREE;

#endif	H_AVL;