System.Text.RegularExpressions.RegexCharClass.RegexCharClass C# (CSharp) Method

        static RegexCharClass() {
            _definedCategories = new Hashtable(31);
            
            char[] groups = new char[9];
            StringBuilder word = new StringBuilder(11);

            word.Append(GroupChar);
            groups[0] = GroupChar;

            // We need the UnicodeCategory enum values as a char so we can put them in a string
            // in the hashtable.  In order to get there, we first must cast to an int, 
            // then cast to a char
            // Also need to distinguish between positive and negative values.  UnicodeCategory is zero 
            // based, so we add one to each value and subtract it off later

            // Others
            groups[1] = (char) ((int) UnicodeCategory.Control + 1);
            _definedCategories["Cc"] = groups[1].ToString();     // Control 
            groups[2] = (char) ((int) UnicodeCategory.Format + 1);
            _definedCategories["Cf"] = groups[2].ToString();     // Format
            groups[3] = (char) ((int) UnicodeCategory.OtherNotAssigned + 1);
            _definedCategories["Cn"] = groups[3].ToString();     // Not assigned
            groups[4] = (char) ((int) UnicodeCategory.PrivateUse + 1);
            _definedCategories["Co"] = groups[4].ToString();     // Private use
            groups[5] = (char) ((int) UnicodeCategory.Surrogate + 1);
            _definedCategories["Cs"] = groups[5].ToString();     // Surrogate

            groups[6] = GroupChar;
            _definedCategories["C"] = new String(groups, 0, 7);

            // Letters
            groups[1] = (char) ((int) UnicodeCategory.LowercaseLetter + 1);
            _definedCategories["Ll"] = groups[1].ToString();     // Lowercase
            groups[2] = (char) ((int) UnicodeCategory.ModifierLetter + 1);
            _definedCategories["Lm"] = groups[2].ToString();     // Modifier
            groups[3] = (char) ((int) UnicodeCategory.OtherLetter + 1);
            _definedCategories["Lo"] = groups[3].ToString();     // Other 
            groups[4] = (char) ((int) UnicodeCategory.TitlecaseLetter + 1);
            _definedCategories["Lt"] = groups[4].ToString();     // Titlecase
            groups[5] = (char) ((int) UnicodeCategory.UppercaseLetter + 1);
            _definedCategories["Lu"] = groups[5].ToString();     // Uppercase

            //groups[6] = GroupChar;
            _definedCategories["L"] = new String(groups, 0, 7);
            word.Append(new String(groups, 1, 5));

            // Marks        
            groups[1] = (char) ((int) UnicodeCategory.SpacingCombiningMark + 1);
            _definedCategories["Mc"] = groups[1].ToString();     // Spacing combining
            groups[2] = (char) ((int) UnicodeCategory.EnclosingMark + 1);
            _definedCategories["Me"] = groups[2].ToString();     // Enclosing
            groups[3] = (char) ((int) UnicodeCategory.NonSpacingMark + 1);
            _definedCategories["Mn"] = groups[3].ToString();     // Non-spacing
            
            groups[4] = GroupChar;
            _definedCategories["M"] = new String(groups, 0, 5);
            //word.Append(groups[1]);
            //word.Append(groups[3]);

            // Numbers
            groups[1] = (char) ((int) UnicodeCategory.DecimalDigitNumber + 1);
            _definedCategories["Nd"] = groups[1].ToString();     // Decimal digit
            groups[2] = (char) ((int) UnicodeCategory.LetterNumber + 1);
            _definedCategories["Nl"] = groups[2].ToString();     // Letter
            groups[3] = (char) ((int) UnicodeCategory.OtherNumber + 1);
            _definedCategories["No"] = groups[3].ToString();     // Other 

            //groups[4] = GroupChar;
            _definedCategories["N"] = new String(groups, 0, 5);
            word.Append(groups[1]);
            //word.Append(new String(groups, 1, 3));

            // Punctuation
            groups[1] = (char) ((int) UnicodeCategory.ConnectorPunctuation + 1);
            _definedCategories["Pc"] = groups[1].ToString();     // Connector
            groups[2] = (char) ((int) UnicodeCategory.DashPunctuation + 1);
            _definedCategories["Pd"] = groups[2].ToString();     // Dash
            groups[3] = (char) ((int) UnicodeCategory.ClosePunctuation + 1);
            _definedCategories["Pe"] = groups[3].ToString();     // Close
            groups[4] = (char) ((int) UnicodeCategory.OtherPunctuation + 1);
            _definedCategories["Po"] = groups[4].ToString();     // Other
            groups[5] = (char) ((int) UnicodeCategory.OpenPunctuation + 1);
            _definedCategories["Ps"] = groups[5].ToString();     // Open
            groups[6] = (char) ((int) UnicodeCategory.FinalQuotePunctuation + 1);
            _definedCategories["Pf"] = groups[6].ToString();     // Inital quote
            groups[7] = (char) ((int) UnicodeCategory.InitialQuotePunctuation + 1);
            _definedCategories["Pi"] = groups[7].ToString();     // Final quote

            groups[8] = GroupChar;
            _definedCategories["P"] = new String(groups, 0, 9);
            word.Append(groups[1]);
            
            // Symbols
            groups[1] = (char) ((int) UnicodeCategory.CurrencySymbol + 1);
            _definedCategories["Sc"] = groups[1].ToString();     // Currency
            groups[2] = (char) ((int) UnicodeCategory.ModifierSymbol + 1);
            _definedCategories["Sk"] = groups[2].ToString();     // Modifier
            groups[3] = (char) ((int) UnicodeCategory.MathSymbol + 1);
            _definedCategories["Sm"] = groups[3].ToString();     // Math
            groups[4] = (char) ((int) UnicodeCategory.OtherSymbol + 1);
            _definedCategories["So"] = groups[4].ToString();     // Other

            groups[5] = GroupChar;
            _definedCategories["S"] = new String(groups, 0, 6);

            // Separators
            groups[1] = (char) ((int) UnicodeCategory.LineSeparator + 1);
            _definedCategories["Zl"] = groups[1].ToString();     // Line
            groups[2] = (char) ((int) UnicodeCategory.ParagraphSeparator + 1);
            _definedCategories["Zp"] = groups[2].ToString();     // Paragraph
            groups[3] = (char) ((int) UnicodeCategory.SpaceSeparator + 1);
            _definedCategories["Zs"] = groups[3].ToString();     // Space
            
            groups[4] = GroupChar;
            _definedCategories["Z"] = new String(groups, 0, 5);


            word.Append(GroupChar);
            Word = word.ToString();
            NotWord = NegateCategory(Word);


            SpaceClass      = "\x00\x00\x01" + Space;
            NotSpaceClass   = "\x01\x00\x01" + Space;
            WordClass       = "\x00\x00" + (char) Word.Length + Word;
            NotWordClass    = "\x01\x00" + (char) Word.Length + Word;;
            DigitClass      = "\x00\x00\x01" + (char) ((int) UnicodeCategory.DecimalDigitNumber + 1);
            NotDigitClass   = "\x00\x00\x01" + unchecked ((char) (- ((int) UnicodeCategory.DecimalDigitNumber + 1)) );

#if DBG
            // make sure the _propTable is correctly ordered
            int len = _propTable.GetLength(0);
            for (int i=0; i<len-1; i++)
                Debug.Assert(String.Compare(_propTable[i,0], _propTable[i+1,0], StringComparison.Ordinal) < 0, "RegexCharClass _propTable is out of order at (" + _propTable[i,0] +", " + _propTable[i+1,0] + ")");
#endif            
        }