private IEnumerable <ColumnSelectionExpression> ParseProjection(NewExpression expression, Expression fieldsParameter)
{
for (var i = 0; i < expression.Arguments.Count; i++)
{
MemberInfo member = expression.Members[i];
var argument = expression.Arguments[i];
switch (argument.NodeType)
{
case ExpressionType.MemberAccess:
yield return(ParseColumnSelection((MemberExpression)argument, member, fieldsParameter));
break;
case ExpressionType.Call:
var call = ((MethodCallExpression)argument);
var fieldSelection = ParseColumnSelection((MemberExpression)call.Arguments[0], member, fieldsParameter);
var aggregation = new FieldAggregationExpression(call.Method.Name);
yield return(new FieldSelectionExpression(fieldSelection, aggregation));
break;
default:
throw new NotImplementedException();
}
}
}
public FieldSelectionExpression(FieldSelectionExpression selection, FieldAggregationExpression aggregation) : base((string)selection.Alias)
{
FieldName = selection.FieldName;
Aggregation = aggregation;
}
