sS formatDouble(double d, int digits) {
  S format = digits <= 0 ? "0" : "0." + rep(digits, '#');
  ret decimalFormatEnglish(format, d);
}

sS formatDouble(double d) {
  ret str(d);
}

ifclass DoubleRange
sS formatDouble(DoubleRange r, int digits) {
  ret r == null ? "null" : "[" + formatDouble(r.start, digits)
    + ";" + formatDouble(r.end, digits) + "]";
}
endif