static L<S> webs_readTripleFile(File f) {
  Iterator<S> it = linesFromFile(f);
  L<S> names = (L) unstructure(it.next());
  new L<Web> webs;
  while (it.hasNext()) {
    S s = it.next();
    pcall {
      L<S> l = splitAtSpace(s);
      if (l(l) == 3)
        webs.add(webFromTriple(
          names.get(parseInt(first(l))), 
          names.get(parseInt(second(l))),
          names.get(parseInt(last(l)))));
    }
  }
  ret webs;
}