［structure] dlist

dlist.c

typedef struct dlist_s dlist_t;

struct dlist_s
{
    dlist_t *next;
    dlist_t *prev;
};

void dlist_init(dlist_t *list)
{
    list->prev = list->next = list;
}

void dlist_append(dlist_t *list, dlist_t *item)
{
    item->next = list;
    item->prev = list->prev;
    item->next->prev = item->prev->next = item;
}

void dlist_prepend(dlist_t *list, dlist_t *item)
{
    item->next = list->next;
    item->prev = list;
    item->next->prev = item->prev->next = item;
}

void dlist_unlink(dlist *item)
{
    item->prev->next = item->next;
    item->next->prev = item->prev;
}

bool dlist_is_empty(dlist_t *list)
{
    return list->next = list;
}
}