Ejemplo n.º 1
0
        private static CalculateExpression Parse(Dictionary <string, MoneyColumnMetadataJsModel> columns, MoneyColumnMetadataJsModel column, string function)
        {
            CalculateExpression currentExpression = new EmptyExpression(column);

            try
            {
                while (function.Length > 0)
                {
                    function = function.Trim();

                    if (function[0] == '[')
                    {
                        var referenceName = function.Substring(1, function.IndexOf(']') - 1);

                        function = function.Remove(0, function.IndexOf(']') + 1);

                        var matchingColumn = columns[referenceName];

                        currentExpression = currentExpression.TryApply(new ReferenceExpression(matchingColumn));
                    }
                    else if (function[0] == '(')
                    {
                        var counter = 1;
                        int i;
                        for (i = 1; i < function.Length && counter > 0; i++)
                        {
                            if (function[i] == '(')
                            {
                                counter++;
                            }
                            if (function[i] == ')')
                            {
                                counter--;
                            }
                        }

                        var sub    = function.Substring(0, i);
                        var subExp = Parse(columns, column, sub.TrimStart('(').TrimEnd(')'));
                        currentExpression = currentExpression.TryApply(new ParenthesisExpression(subExp));

                        function = function.Substring(i);
                    }
                    else if (function[0] == '{')
                    {
                        var constant = function.Substring(1, function.IndexOf('}') - 1);

                        function = function.Remove(0, function.IndexOf('}') + 1);

                        currentExpression = currentExpression.TryApply(new ConstantExpression(column, constant));
                    }
                    else
                    {
                        var symbol = BinaryExpression.Symbols.FirstOrDefault(function.StartsWith);
                        if (symbol != null)
                        {
                            currentExpression = new BinaryExpression(column, symbol).TryApply(currentExpression);
                            function          = function.Substring(symbol.Length);
                        }
                        else
                        {
                            return(new FailedToParseExpression(column, function));
                        }
                    }
                }
            }
            catch
            {
                return(new FailedToParseExpression(column, function));
            }

            return(currentExpression);
        }