public static string ExpandCharClass(string charClass)
{
var regexParser = new RegexParser(CultureInfo.CurrentCulture);
regexParser.SetPattern(charClass);
var regexCharClass = regexParser.ScanCharClass(false);
int count = regexCharClass.RangeCount();
List <string> ranges = new List <string>();
// range 0 can be skipped
for (int i = 1; i < count; i++)
{
var range = regexCharClass.GetRangeAt(i);
ranges.Add(ExpandRange(range));
}
return(String.Concat(ranges));
}