/// <summary>
/// Builds a predicate from multiple character types
/// </summary>
/// <param name="charTypes"></param>
/// <returns></returns>
private static Func <char, bool> CharFunc(CharTypes charTypes)
{
var predicates = new Collection <Func <char, bool> >();
// Letters or Digits
if (charTypes.HasFlags(CharTypes.LettersOrDigits))
{
predicates.Add(char.IsLetterOrDigit);
}
else if (charTypes.HasFlags(CharTypes.Letters))
{
predicates.Add(char.IsLetter);
}
else if (charTypes.HasFlags(CharTypes.Digits))
{
predicates.Add(char.IsDigit);
}
// XML
if (charTypes.HasFlags(CharTypes.XmlChar))
{
predicates.Add(XmlConvert.IsXmlChar);
}
// White space
if (charTypes.HasFlags(CharTypes.WhiteSpace))
{
predicates.Add(char.IsWhiteSpace);
}
switch (predicates.Count)
{
case 1: return(predicates[0]);
case 2: return(c => predicates[0](c) || predicates[1](c));
case 3: return(c => predicates[0](c) || predicates[1](c) || predicates[2](c));
}
return(null);
// //unfortunately, this slows things way down - if anyone knows of a better
// //way to combine predicates, please weigh in!
//return c => predicates.Any(p => p(c));
}
