/// <summary> returns the lexer that's gonna parse a hex integer number (valid patterns are: 0x1, 0Xff, 0xFe1 jfun.yan.etc.),
/// and convert the string to a Long token.
/// an hex number has to start with either 0x or 0X.
/// </summary>
/// <returns> the lexer.
/// </returns>
public static Lexer LexHexLong()
{
string name = "hex integer literal";
return(Lex(Scanners.Delimited(Scanners.IsPattern(name, Patterns.IsHexInteger(), "hexInteger")),
Tokenizers.ForHexLong).Rename(name));
}