System.Xml.Xsl.Runtime.NumberFormatter.FormatItem C# (CSharp) Method

        private void FormatItem(StringBuilder sb, XPathItem item, char startChar, int length) {
            double dblVal;

            if (item.ValueType == typeof(int)) {
                dblVal = (double)item.ValueAsInt;
            } else {
                Debug.Assert(item.ValueType == typeof(double), "Item must be either of type int, or double");
                dblVal = XsltFunctions.Round(item.ValueAsDouble);
            }

            Debug.Assert(1 <= dblVal && dblVal < double.PositiveInfinity);
            char zero = '0';

            switch (startChar) {
            case '1':
                break;
            case 'A':
            case 'a':
                if (dblVal <= MaxAlphabeticValue) {
                    ConvertToAlphabetic(sb, dblVal, startChar, 26);
                    return;
                }
                break;
            case 'I':
            case 'i':
                if (dblVal <= MaxRomanValue) {
                    ConvertToRoman(sb, dblVal, /*upperCase:*/ startChar == 'I');
                    return;
                }
                break;
            default:
                Debug.Assert(CharUtil.IsDecimalDigitOne(startChar), "Unexpected startChar: " + startChar);
                zero = (char)(startChar - 1);
                break;
            }

            sb.Append(ConvertToDecimal(dblVal, length, zero, groupingSeparator, groupingSize));
        }