source: protocols/yahoo/yahoo_list.c @ bad4a586

/*
 * yahoo_list.c: linked list routines
 *
 * Some code copyright (C) 2002-2004, Philip S Tellis <philip.tellis AT gmx.net>
 * Other code copyright Meredydd Luff <meredydd AT everybuddy.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
 *
 * Some of this code was borrowed from elist.c in the eb-lite sources
 *
 */

#include <stdlib.h>

#include "yahoo_list.h"

YList *y_list_append(YList * list, void *data)
{
        YList *n;
        YList *new_list = malloc(sizeof(YList));
        YList *attach_to = NULL;

        new_list->next = NULL;
        new_list->data = data;

        for (n = list; n != NULL; n = n->next) {
                attach_to = n;
        }

        if (attach_to == NULL) {
                new_list->prev = NULL;
                return new_list;
        } else {
                new_list->prev = attach_to;
                attach_to->next = new_list;
                return list;
        }
}

YList *y_list_prepend(YList * list, void *data)
{
        YList *n = malloc(sizeof(YList));

        n->next = list;
        n->prev = NULL;
        n->data = data;
        if (list)
                list->prev = n;

        return n;
}

YList *y_list_concat(YList * list, YList * add)
{
        YList *l;

        if(!list)
                return add;

        if(!add)
                return list;

        for (l = list; l->next; l = l->next)
                ;

        l->next = add;
        add->prev = l;

        return list;
}

YList *y_list_remove(YList * list, void *data)
{
        YList *n;

        for (n = list; n != NULL; n = n->next) {
                if (n->data == data) {
                        list=y_list_remove_link(list, n);
                        y_list_free_1(n);
                        break;
                }
        }

        return list;
}

/* Warning */
/* link MUST be part of list */
/* caller must free link using y_list_free_1 */
YList *y_list_remove_link(YList * list, const YList * link)
{
        if (!link)
                return list;

        if (link->next)
                link->next->prev = link->prev;
        if (link->prev)
                link->prev->next = link->next;

        if (link == list)
                list = link->next;
        
        return list;
}

int y_list_length(const YList * list)
{
        int retval = 0;
        const YList *n = list;

        for (n = list; n != NULL; n = n->next) {
                retval++;
        }

        return retval;
}

/* well, you could just check for list == NULL, but that would be
 * implementation dependent
 */
int y_list_empty(const YList * list)
{
        if(!list)
                return 1;
        else
                return 0;
}

int y_list_singleton(const YList * list)
{
        if(!list || list->next)
                return 0;
        return 1;
}

YList *y_list_copy(YList * list)
{
        YList *n;
        YList *copy = NULL;

        for (n = list; n != NULL; n = n->next) {
                copy = y_list_append(copy, n->data);
        }

        return copy;
}

void y_list_free_1(YList * list)
{
        free(list);
}

void y_list_free(YList * list)
{
        YList *n = list;

        while (n != NULL) {
                YList *next = n->next;
                free(n);
                n = next;
        }
}

YList *y_list_find(YList * list, const void *data)
{
        YList *l;
        for (l = list; l && l->data != data; l = l->next)
                ;

        return l;
}

void y_list_foreach(YList * list, YListFunc fn, void * user_data)
{
        for (; list; list = list->next)
                fn(list->data, user_data);
}

YList *y_list_find_custom(YList * list, const void *data, YListCompFunc comp)
{
        YList *l;
        for (l = list; l; l = l->next)
                if (comp(l->data, data) == 0)
                        return l;

        return NULL;
}

YList *y_list_nth(YList * list, int n)
{
        int i=n;
        for ( ; list && i; list = list->next, i--)
                ;

        return list;
}

YList *y_list_insert_sorted(YList * list, void *data, YListCompFunc comp)
{
        YList *l, *n, *prev = NULL;
        if (!list)
                return y_list_append(list, data);

        n = malloc(sizeof(YList));
        n->data = data;
        for (l = list; l && comp(l->data, n->data) <= 0; l = l->next)
                prev = l;

        if (l) {
                n->prev = l->prev;
                l->prev = n;
        } else
                n->prev = prev;

        n->next = l;

        if(n->prev) {
                n->prev->next = n;
                return list;
        } else {
                return n;
        }
                
}