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/*****************************************************************************
*
* Usepackage Environment Manager
* Copyright (C) 1995-2015 Jonathan Hogg <me@jonathanhogg.com>
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Name : linked_list.c
* Author : Jonathan Hogg <me@jonathanhogg.com>
*
****************************************************************************/
/* linked_list.c */
/* polymorphic linked-list ADT */
/* Jonathan AH Hogg */
/*
* Assumes that the values are pointers to some 'alloc'ed data structures,
* as 'remove_node' will attempt to 'free' the value pointer.
*/
#include <stdio.h>
#include <stdlib.h>
#include "linked_list.h"
list_node* new_node(void)
{
list_node *node;
node = (list_node*) malloc(sizeof(list_node));
return(node);
} /* new_node */
linked_list* new_list(void)
{
linked_list *list;
list = (linked_list*) malloc(sizeof(linked_list));
list->head = NULL;
list->tail = NULL;
return(list);
} /* new_list */
list_node* add_to_head(linked_list* l, void* s)
{
list_node *node;
node = new_node();
node->value = s;
node->next = l->head;
node->previous = NULL;
if (l->head)
l->head->previous = node;
if (!l->tail)
l->tail = node;
l->head = node;
return(node);
} /* add_to_head */
list_node* add_to_tail(linked_list* l, void* s)
{
list_node *node;
node = new_node();
node->value = s;
node->next = NULL;
node->previous = l->tail;
if (l->tail)
l->tail->next = node;
if (!l->head)
l->head = node;
l->tail = node;
return(node);
} /* add_to_tail */
void remove_node(linked_list* l, list_node* n, int k)
{
if (n->previous)
n->previous->next = n->next;
else
l->head = n->next;
if (n->next)
n->next->previous = n->previous;
else
l->tail = n->previous;
if (k) free(n->value);
free(n);
} /* remove_node */
void free_list(linked_list* l, int k)
{
list_node *node;
list_node *next_node;
node = l->head;
while (node)
{
if (k) free(node->value);
next_node = node->next;
free(node);
node = next_node;
}
free(l);
} /* free_list */
list_node* head(linked_list* l)
{
return(l->head);
} /* head */
list_node* list_tail(linked_list* l)
{
return(l->tail);
} /* list_tail */
list_node* next(list_node* n)
{
return(n->next);
} /* next */
list_node* previous(list_node* n)
{
return(n->previous);
} /* previous */
void* get_value(list_node* n)
{
return(n->value);
} /* value */
void set_value(list_node* n, void* s)
{
n->value = s;
} /* value */
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