sS htmlencode_noQuotes(S s) {
  if (s == null) ret "";
  int n = s.length();
  StringBuilder out = null;
  
  macro builder {
    out if null = new StringBuilder(Math.max(16, n)).append(takeFirst(i, s));
    out
  }
  
  for i to n: {
    char c = s.charAt(i);
    if (c == '<') {
      builder.append("&lt;");
    }
    else if (c == '>') {
      builder.append("&gt;");
    }
    else if (c > 127 || c == '&') {
      int cp = s.codePointAt(i);
      builder.append("&#x");
      out.append(intToHex_flexLength(cp));
      out.append(';');
      i += Character.charCount(cp)-1;
    } else
      out?.append(c);
  }
  ret out == null ? s : out.toString();
}

Began life as a copy of #1001263