Lucene.Net.QueryParsers.Surround.Parser.QueryParserTokenManager.GetNextToken C# (CSharp) Method

        public virtual Token GetNextToken()
        {
            Token matchedToken;
            int curPos = 0;

            for (; ; )
            {
                try
                {
                    curChar = input_stream.BeginToken();
                }
                catch (System.IO.IOException /*e*/)
                {
                    jjmatchedKind = 0;
                    matchedToken = JjFillToken();
                    return matchedToken;
                }

                switch (curLexState)
                {
                    case 0:
                        jjmatchedKind = 0x7fffffff;
                        jjmatchedPos = 0;
                        curPos = JjMoveStringLiteralDfa0_0();
                        break;
                    case 1:
                        jjmatchedKind = 0x7fffffff;
                        jjmatchedPos = 0;
                        curPos = jjMoveStringLiteralDfa0_1();
                        break;
                }
                if (jjmatchedKind != 0x7fffffff)
                {
                    if (jjmatchedPos + 1 < curPos)
                        input_stream.BackUp(curPos - jjmatchedPos - 1);
                    if ((jjtoToken[jjmatchedKind >> 6] & (1L << (jjmatchedKind & 63 /*077*/))) != 0L)
                    {
                        matchedToken = JjFillToken();
                        if (jjnewLexState[jjmatchedKind] != -1)
                            curLexState = jjnewLexState[jjmatchedKind];
                        return matchedToken;
                    }
                    else
                    {
                        if (jjnewLexState[jjmatchedKind] != -1)
                            curLexState = jjnewLexState[jjmatchedKind];
                        goto EOFLoop;
                    }
                }
                int error_line = input_stream.EndLine;
                int error_column = input_stream.EndColumn;
                string error_after = null;
                bool EOFSeen = false;
                try { input_stream.ReadChar(); input_stream.BackUp(1); }
                catch (System.IO.IOException /*e1*/)
                {
                    EOFSeen = true;
                    error_after = curPos <= 1 ? "" : input_stream.Image;
                    if (curChar == '\n' || curChar == '\r')
                    {
                        error_line++;
                        error_column = 0;
                    }
                    else
                        error_column++;
                }
                if (!EOFSeen)
                {
                    input_stream.BackUp(1);
                    error_after = curPos <= 1 ? "" : input_stream.Image;
                }
                throw new TokenMgrError(EOFSeen, curLexState, error_line, error_column, error_after, curChar, TokenMgrError.LEXICAL_ERROR);
            EOFLoop: ;
            }
        }