-/** Given a vector of indices, split them into two vectors, one containing
- * the free indices, the other containing the dummy indices. */
-static void find_free_and_dummy(exvector::const_iterator it, exvector::const_iterator itend, exvector & out_free, exvector & out_dummy)
-{
- out_free.clear();
- out_dummy.clear();
-
- // No indices? Then do nothing
- if (it == itend)
- return;
-
- // Only one index? Then it is a free one if it's not numeric
- if (itend - it == 1) {
- if (ex_to_idx(*it).is_symbolic())
- out_free.push_back(*it);
- return;
- }
-
- // Sort index vector. This will cause dummy indices come to lie next
- // to each other (because the sort order is defined to guarantee this).
- exvector v(it, itend);
- sort_index_vector(v);
-
- // Find dummy pairs and free indices
- it = v.begin(); itend = v.end();
- exvector::const_iterator last = it++;
- while (it != itend) {
- if (is_dummy_pair(*it, *last)) {
- out_dummy.push_back(*last);
- it++;
- if (it == itend)
- return;
- } else {
- if (!it->is_equal(*last) && ex_to_idx(*last).is_symbolic())
- out_free.push_back(*last);
- }
- last = it++;
- }
- if (ex_to_idx(*last).is_symbolic())
- out_free.push_back(*last);
-}
-