public static T Evaluate <T>(DataElement data, Row row, List <Index> usedIndexes, string formula, int columnIndex = 0)
{
IEnumerable <Index> actualUsedIndexes = usedIndexes.Where(i => data.HasColumn(i));
string expressionText = formula.ToLower();
Expression expression = new Expression(expressionText);
foreach (Index usedColumnIndex in actualUsedIndexes)
{
object dataItemValue = null;
string name = usedColumnIndex.Name;
if (usedColumnIndex.Number.HasValue)
{
dataItemValue = row[usedColumnIndex.Number.Value];
name = "c#" + usedColumnIndex.Number.Value;
}
else
{
dataItemValue = row[usedColumnIndex.Name];
}
AddParameter(expression, name.ToLower(), dataItemValue);
}
if (expressionText.Contains("[value]"))
{
AddParameter(expression, "value", row[columnIndex]);
}
T result = (T)expression.Evaluate();
return(result);
}