#include <u.h>
#include <libn.h>
#include <libbio.h>

error
phylo·addchild(bio·Node* parent, bio·Node* child)
{
    bio·Node *it, *sibling;
    switch (parent->nchild) {
    case 1:
        parent->child[0]->sibling = child;
    case 0:
        parent->child[parent->nchild++] = child;
    break;

    default:
        sibling = parent->child[1];
        for (it = parent->child[1]->sibling; it != nil; it = it->sibling) {
            sibling = it;
        }
        sibling->sibling = child;
        parent->nchild++;
    }

    child->parent = parent;
    return 0;
}