/* Intern */
void *find(Mapnode *first, void *key, Cmpfn_ptr cmpfn) {
  if (!first)
    return NULL;
  else if (cmpfn(key, first->key) == 0)
    return first->val;
  else if (cmpfn(key, first->key) < 0)
    return find(first->left, key, cmpfn);
  else
    return find(first->right, key, cmpfn);
}

/* Gränssnittsfunktion */
void *findmap(Maphead *map, void *key) {
  return find(map->first, key, map->cfn);
}