/*
Libraries for fields, doubly-linked lists and red-black trees.
Copyright (C) 2001 James S. Plank

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

---------------------------------------------------------------------------
Please see http://web.eecs.utk.edu/~jplank/plank/classes/cs360/360/notes/Libfdr/
for instruction on how to use this library.

Jim Plank
plank@cs.utk.edu
http://web.eecs.utk.edu/~jplank

Associate Professor
Department of Computer Science
University of Tennessee
203 Claxton Complex
1122 Volunteer Blvd.
Knoxville, TN 37996-3450

     865-974-4397
Fax: 865-974-4404
*/


/* Revision Date: 9/09
 * Modified by Brad Vander Zanden in the following ways:
 * 
 * 1) Added a container object to point to the sentinel node
 * 2) Changed the val field from a JVal to a void *
 * 3) Changed the names of the flink and blink fields to next and prev
 * 4) Changed the typedef to a node from a pointer to a struct to a simple struct and
 *     appropriately modified the return values and parameter lists of the functions
 */

#ifndef _DLLIST_H_
#define _DLLIST_H_

typedef struct dllist_node {
  struct dllist_node *next;
  struct dllist_node *prev;
  void *val;
} Dllist_Node;

typedef struct {
  Dllist_Node *sentinel_node;
} Dllist;

extern Dllist *new_dllist();
extern void free_dllist(Dllist *l);
extern Dllist_Node *dll_prepend(Dllist *l, void *val);
extern Dllist_Node *dll_append(Dllist *l, void *val);
extern Dllist_Node *dll_insert_before(Dllist_Node *n, void *val);
extern Dllist_Node *dll_insert_after(Dllist_Node *n, void *val);
extern void dll_delete_node(Dllist_Node *n);
extern Dllist_Node *dll_sentinel(Dllist *l);
extern Dllist_Node *dll_first(Dllist *l);
extern Dllist_Node *dll_last(Dllist *l);
extern Dllist_Node *dll_next(Dllist_Node *n);
extern Dllist_Node *dll_prev(Dllist_Node *n);
extern int dll_empty(Dllist *l);
extern void *dll_val(Dllist_Node *n);

#endif