scope tok_conditionals

// returns number of changes
static int tok_conditionals(LS tok, S keyword, S keywordEnd, IPred<S> pred, bool reTokImmediately, bool noReTok) {
  int changes = 0;
  if (tok instanceof IContentsIndexedList) {
    int[] l = tok/IContentsIndexedList.indicesOf(keyword);
    for (int j = l(l)-1; j >= 0; j--) {
      int i = l[j];
      if (isIdentifier(get(tok, i+2))) {
        processConditional(tok, i, keyword, keywordEnd, pred, reTokImmediately && !noReTok);
        ++changes;
      }
    }
  } else {
    if (!tok.contains(keyword)) ret changes;
    int i = l(tok);
    while ((i = rjfind(tok, 1, i-1, keyword + " <id>")) >= 0) {
      ++changes;
      processConditional(tok, i, keyword, keywordEnd, pred, reTokImmediately && !noReTok);
    }
  }
  if (changes != 0 && !reTokImmediately && !noReTok) reTok(tok);
  //print(keyword + ": " + nChanges(changes));
  ret changes;
}

svoid #processConditional(LS tok, int i, S keyword, S keywordEnd, IPred<S> pred, bool reTokImmediately) {
  int j = jfind(tok, i+4, keywordEnd);
  if (j < 0) j = l(tok)-1;
  S name = tok.get(i+2);
  bool has = pred.get(name);
  //print(keyword + " " + name + " => " + has);
  if (has) {
    clearTokens_maybeReTok(tok, j, j+1, reTokImmediately);
    clearTokens_maybeReTok(tok, i, i+3, reTokImmediately);
  } else
    clearTokens_maybeReTok(tok, i, j+1, reTokImmediately); // safer than before
}