UniversalMarkdown.Parse.Elements.ListBlock.ParseItemPreamble C# (CSharp) Method

        private static ListItemPreamble ParseItemPreamble(string markdown, int start, int maxEnd)
        {
            // There are two types of lists.
            // A numbered list starts with a number, then a period ('.'), then a space.
            // A bulleted list starts with a star ('*'), dash ('-') or plus ('+'), then a period, then a space.
            ListStyle style;
            if (markdown[start] == '*' || markdown[start] == '-' || markdown[start] == '+')
            {
                style = ListStyle.Bulleted;
                start++;
            }
            else if (markdown[start] >= '0' && markdown[start] <= '9')
            {
                style = ListStyle.Numbered;
                start++;

                // Skip any other digits.
                while (start < maxEnd)
                {
                    char c = markdown[start];
                    if (c < '0' || c > '9')
                        break;
                    start++;
                }

                // Next should be a period ('.').
                if (start == maxEnd || markdown[start] != '.')
                    return null;
                start++;
            }
            else
                return null;

            // Next should be a space.
            if (start == maxEnd || (markdown[start] != ' ' && markdown[start] != '\t'))
                return null;
            start++;

            // This is a valid list item.
            return new ListItemPreamble { Style = style, ContentStartPos = start };
        }