sS lcStream_textWithBrackets(LCStreamingCompressor lc) {
  new StringBuilder buf;
  lcStream_textWithBrackets_step(lc, buf, lc.chain.toList());
  ret str(buf);
}
  
svoid lcStream_textWithBrackets_step(LCStreamingCompressor lc, StringBuilder buf, L<Int> chunks) {
  for (int idx : chunks) {
    LCStreamingCompressor.Chunk c = lc.chunks.get(idx);
    if (c cast LCStreamingCompressor.CPair) {
      buf.append("(");
      lcStream_textWithBrackets_step(lc, buf, ll(c.i1, c.i2));
      buf.append(")");
    } else
      buf.append(((LCStreamingCompressor.CPrim) c).c);    
  }
}

Began life as a copy of #1028482