sS newLinesToSpaces_keepCharCount(S s) {
  int n = l(s);
  StringBuilder buf = new(n);
  for i to n: {
    char c = s.charAt(i);
    if (c == '\t' || c == '\r' || c == '\n')
      c = ' ';
    buf.append(c);
  }
  ret str(buf);
}