8.6 Copying

We can use the tree copy function for TBSTs almost verbatim here. The one necessary change is that copy_node() must copy node balance factors. Here's the new version:

330. <TAVL node copy function 330> =
static int 
copy_node (struct tavl_table *tree, 
           struct tavl_node *dst, int dir,
           const struct tavl_node *src, tavl_copy_func *copy) 
{
  struct tavl_node *new = 
    tree->tavl_alloc->libavl_malloc (tree->tavl_alloc, sizeof *new);
  if (new == NULL)
    return 0;

  new->tavl_link[dir] = dst->tavl_link[dir];
  new->tavl_tag[dir] = TAVL_THREAD;
  new->tavl_link[!dir] = dst;
  new->tavl_tag[!dir] = TAVL_THREAD;
  dst->tavl_link[dir] = new;
  dst->tavl_tag[dir] = TAVL_CHILD;

  new->tavl_balance = src->tavl_balance;
  if (copy == NULL)
    new->tavl_data = src->tavl_data;
  else 
    {
      new->tavl_data = copy (src->tavl_data, tree->tavl_param);
      if (new->tavl_data == NULL)
        return 0;
    }

  return 1;
}

This code is included in 331.

331. <TAVL copy function 331> =
<TAVL node copy function 330>
<TBST copy error helper function; tbst => tavl 282>
<TBST main copy function; tbst => tavl 281>

This code is included in 302 and 338.