svoid nlLogic_flexMatch_iterate(S pat, S input, NLLogicChecker_v2.Matching m, onMatch, LinkedHashMap<S> oldMatches) {
  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)) ret;
  }
  LL<S> spreadInputs = ai_spreadCertainIndices(tokPat, tokInput, varIndices);
  for (L<S> tok : spreadInputs) {
    SS newMatches = matchDollarVarsIC(pat, tok);
    if (newMatches != null && addMapToMapWithoutOverwritingIC(m.matches, newMatches))
      try { callF(onMatch); } finally { m.matches = oldMatches; }
  }
}