static L<S> splitIntoSentences_v2(S s, O... _) {
  ret splitIntoSentences_v2_tok(nlTok3(s), _);
}

static Cl<S> splitIntoSentences_v2_tok_endMarkers = litset(".", "?", "!");

static L<S> splitIntoSentences_v2_tok(L<S> s, O... _) {
  optPar Cl<S> endMarkers = splitIntoSentences_v2_tok_endMarkers;
  int i = 0;
  new L<S> l;
  while (i < l(s)) {
    int j;
    if (emptyAfterTrim(s.get(i)) && isRoundBracketed(get(s, i+1)))
      j = i+2;
    else
      j = smartIndexOfAny(s, i, endMarkers)+1;
    addIfNempty(l, trimJoinSubList(s, i, j));
    i = j;
  }
  ret l;
}

Began life as a copy of #1008429