static Set<S> magicQuotes(S input) {
  new LinkedHashSet<S> out;
  magicQuotes_impl(new L, asLinkedList(javaTok(input)), false, out);
  ret out;
}

// Q: do remainingTokens start with an N or C token?
svoid magicQuotes_impl(LS tokens, LS remainingTokens, bool inQuote, Set<S> out) {
  if (l(remainingTokens) < 2)
    out.add(join(tokens));
  else {
    // case 1: don't insert a quote
    
    tokens.add(takeFirst(2, remainingTokens));
    removeFirst(2, remainingTokens);
    magicQuotes_impl(tokens, remainingTokens, inQuote, out);
    remainingTokens.addAll(popLast(2, tokens));
    
    // case 2: insert quote
  }
}