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; }
  }
}