Method convert

src/cnf.cpp:384–435

convert CNF-normalized operator tree to terms, a CNF AND-list of ALT-term lists

// convert CNF-normalized operator tree to terms, a CNF AND-list of ALT-term lists
void CNF::OpTree::convert(Terms& terms)
{
  if (op == OpTree::AND)
  {
    for (const auto& i : list)
    {
      if (!terms.back().empty())
        terms.emplace_back();

      if (i.op == OpTree::OR)
      {
        auto k = i.list.begin();
        auto e = i.list.end();

        while (k != e && (k->op != NONE || !k->regex.empty()))
          ++k;

        if (k != e)
        {
          // empty pattern found, ignore all other patterns
          k->add_to(terms);
        }
        else
        {
          for (const auto& j : i.list)
            j.add_to(terms);
        }
      }
      else
      {
        i.add_to(terms);
      }

      if (terms.back().empty())
      {
        // pop unused ending '|' (or BRE '\|')
        terms.pop_back();
        if (flag_basic_regexp)
          terms.pop_back();
      }
    }
  }
  else if (op == OpTree::OR)
  {
    for (const auto& i : list)
      i.add_to(terms);
  }
  else
  {
    add_to(terms);
  }
}

// add a [NOT] term of the operator tree to terms
void CNF::OpTree::add_to(Terms& terms) const