BalticAmadeus.FluentMdx.MdxParser.TryParseExpression C# (CSharp) Method

        internal static bool TryParseExpression(IStatedTwoWayEnumerator<Token> enumerator, out MdxExpressionBase expression)
        {
            enumerator.SavePosition();
            expression = null;

            var mdxExpression = Mdx.Expression();

            //TODO: Think how to apply NOT and -
            do
            {
                MdxExpressionBase childExpression;
                if (TryParseFunction(enumerator, out childExpression))
                {
                    mdxExpression.WithOperand((MdxFunction) childExpression);
                }
                else if (TryParseTuple(enumerator, out childExpression))
                {
                    mdxExpression.WithOperand((MdxTuple)childExpression);
                }
                else if (TryParseSet(enumerator, out childExpression))
                {
                    mdxExpression.WithOperand((MdxSet)childExpression);
                }
                else if (TryParseRange(enumerator, out childExpression))
                {
                    mdxExpression.WithOperand((MdxRange)childExpression);
                }
                else if (TryParseMember(enumerator, out childExpression))
                {
                    mdxExpression.WithOperand((MdxMember)childExpression);
                }
                else if (TryParseConstantValue(enumerator, out childExpression))
                {
                    mdxExpression.WithOperand((MdxConstantExpression)childExpression);
                }
                else if (IsNextTokenValid(enumerator, TokenType.NotOperator))
                {
                    if (!TryParseExpression(enumerator, out childExpression))
                    {
                        enumerator.RestoreLastSavedPosition();
                        return false;
                    }

                    mdxExpression.WithOperand(((MdxExpression)childExpression).AsNegated());
                }
                else if (IsNextTokenValid(enumerator, TokenType.LeftRoundBracket))
                {
                    if (!TryParseExpression(enumerator, out childExpression))
                    {
                        enumerator.RestoreLastSavedPosition();
                        return false;
                    }

                    mdxExpression.WithOperand((MdxExpression)childExpression);

                    if (!IsNextTokenValid(enumerator, TokenType.RightRoundBracket))
                    {
                        enumerator.RestoreLastSavedPosition();
                        return false;
                    }
                }
                else
                {
                    enumerator.RestoreLastSavedPosition();
                    return false;
                }

                if (!IsNextTokenValid(enumerator, TokenType.MathsOperator) &&
                    !IsNextTokenValid(enumerator, TokenType.LogicsOperator))
                    break;

                mdxExpression.WithOperator(enumerator.Current.Value);

            } while (true);

            expression = mdxExpression;

            enumerator.RemoveLastSavedState();
            return true;
        }