Antlr4.StringTemplate.StringRenderer.ToString C# (CSharp) Method

        public virtual string ToString(object o, string formatString, CultureInfo culture)
        {
            string s = (string)o;
            if (formatString == null)
                return s;

            if (formatString.Equals("upper"))
                return culture.TextInfo.ToUpper(s);

            if (formatString.Equals("lower"))
                return culture.TextInfo.ToLower(s);

            if (formatString.Equals("cap"))
                return s.Length > 0 ? culture.TextInfo.ToUpper(s[0]) + s.Substring(1) : s;

            if (formatString.Equals("url-encode"))
                return HttpUtility.UrlEncode(s, Encoding.UTF8);

            if (formatString.Equals("xml-encode"))
            {
            #if NETSTANDARD
                return s.Replace("&", "&")
                    .Replace("<", "&lt;")
                    .Replace(">", "&gt;")
                    .Replace("\"", "&quot;")
                    .Replace("'", "&apos;");
            #else
                return SecurityElement.Escape(s);
            #endif
            }

            return string.Format(culture, formatString, s);
        }