sbool nlLogic_flexMatch_iterate_debug;

svoid nlLogic_flexMatch_iterate(S pat, S input, NLLogicChecker_v2.Matching m, Runnable onMatch, VarMatches oldMatches) {

  if (nlLogic_flexMatch_iterate_debug)

    print("nlLogic_flexMatch_iterate " + pat + " / " + input);

  L<S> tokPat = parse3_cachedPattern(pat), tokInput = parse3_cachedInput(input);

  // fail if crucial words not found (could be optimized more)

  new L<Int> varIndices;

  for (int i = 1; i < l(tokPat); i += 2) {

    S t = tokPat.get(i);

    if (isDollarVar(t))

      varIndices.add(i);

    else if (isIdentifier(t) && !cicAtOddPosition(tokInput, t)) {

      if (nlLogic_flexMatch_iterate_debug)

        print("Crucial word fail (" + t + "): " + pat + " / " + input);

      ret;

    }

  }

  if (nlLogic_flexMatch_iterate_debug)

    printStructs(+varIndices, +tokPat, +tokInput);

  LL<S> spreadInputs = ai_spreadCertainIndices(tokPat, tokInput, varIndices);

  for (L<S> tok : spreadInputs) {

    if (nlLogic_flexMatch_iterate_debug)

      print("Testing spread input: " + sfu(tok));

    SS newMatches = matchDollarVarsIC(pat, tok);

    if (newMatches != null && addMapToMapWithoutOverwritingIC(m.matches, newMatches))

      try { callF(onMatch); } finally { m.matches = oldMatches; }

  }

}