Item * insert_item(Item *list, Item *item, int position) {
assert(list != NULL);
assert(item != NULL);
assert(position >= 0);
if (position == 0) {
return prepend_item(list, item);
}
Item *current_item = list;
// In order to insert a new item, we must find the item 1 position before the
// desired insert position.
int i = position - 1;
while(--i && current_item != NULL) {
current_item = current_item->next_item;
}
if (current_item == NULL) {
return append_item(list, item);
}
// Insert the new item
Item *temp = current_item->next_item;
current_item->next_item = item;
item->next_item = temp;
return list;
}
item& item::prepend()
{
return *prepend_item(parent_item?(new item(parent_item)):(new item(relation_ptr)));
}
item& item::prepend(item& other)
{
return *prepend_item(parent_item?(new item(other,parent_item)):(new item(other,relation_ptr)));
}
