Antlr4.StringTemplate.Compiler.TemplateLexer.MatchUnicode C# (CSharp) Метод

        private IToken MatchUnicode()
        {
            Consume();
            char[] chars = new char[4];
            if (!IsUnicodeLetter(c))
            {
                NoViableAltException e = new NoViableAltException(string.Empty, 0, 0, input);
                errMgr.LexerError(input.SourceName,string.Format( "invalid unicode char: '{0}'", GetCharString(c)), templateToken, e);
            }

            chars[0] = c;
            Consume();
            if (!IsUnicodeLetter(c))
            {
                NoViableAltException e = new NoViableAltException(string.Empty, 0, 0, input);
                errMgr.LexerError(input.SourceName, string.Format("invalid unicode char: '{0}'", GetCharString(c)), templateToken, e);
            }

            chars[1] = c;
            Consume();
            if (!IsUnicodeLetter(c))
            {
                NoViableAltException e = new NoViableAltException(string.Empty, 0, 0, input);
                errMgr.LexerError(input.SourceName, string.Format("invalid unicode char: '{0}'", GetCharString(c)), templateToken, e);
            }

            chars[2] = c;
            Consume();
            if (!IsUnicodeLetter(c))
            {
                NoViableAltException e = new NoViableAltException(string.Empty, 0, 0, input);
                errMgr.LexerError(input.SourceName, string.Format("invalid unicode char: '{0}'", GetCharString(c)), templateToken, e);
            }

            chars[3] = c;
            // ESCAPE kills >
            char uc = (char)int.Parse(new string(chars), NumberStyles.HexNumber);
            IToken t = NewToken(TEXT, uc.ToString(), input.CharPositionInLine - 6);
            Consume();
            Match(delimiterStopChar);
            return t;
        }