Boo.Lang.Parser.BooLexer.mDIGIT_GROUP C# (CSharp) Method

        protected void mDIGIT_GROUP(bool _createToken)
        {
            int _ttype; IToken _token=null; int _begin=text.Length;
            _ttype = DIGIT_GROUP;

            mDIGIT(false);
            {    // ( ... )*
            for (;;)
            {
                switch ( cached_LA1 )
                {
                case '_':
                {
                    {
                        int _saveIndex = 0;
                        _saveIndex = text.Length;
                        match('_');
                        text.Length = _saveIndex;
                        mDIGIT(false);
                        mDIGIT(false);
                        mDIGIT(false);
                    }
                    break;
                }
                case '0':  case '1':  case '2':  case '3':
                case '4':  case '5':  case '6':  case '7':
                case '8':  case '9':
                {
                    mDIGIT(false);
                    break;
                }
                default:
                {
                    goto _loop851_breakloop;
                }
                 }
            }
            _loop851_breakloop:			;
            }    // ( ... )*
            if (_createToken && (null == _token) && (_ttype != Token.SKIP))
            {
            _token = makeToken(_ttype);
            _token.setText(text.ToString(_begin, text.Length-_begin));
            }
            returnToken_ = _token;
        }