// func : func(LS tok, int iOpening, int iClosing) -> S[] {beg, end}
static L<S> replaceKeywordBlock_dyn2_legacy(L<S> tok, S keyword, O func) {
  for (int i = 0; i < 1000; i++) {
    //int idx = findCodeTokens(tok, keyword, "{");
    int idx = jfind(tok, keyword + " {");
    if (idx < 0)
      break;
    int idx2 = findCodeTokens(tok, idx, false, "{");
    int j = findEndOfBracketPart(tok, idx2);
    
    S[] be = (S[]) callF(func, tok, idx2, j-1);
    replaceTokens(tok, idx, idx2+2, be[0] + " ");
    tok.set(j-1, be[1]);
    reTok(tok, idx, j);
  }
  ret tok;
}

Began life as a copy of #1018806