private Expression AggregateAndReduce(Expression expr)
{
var aggregator = new Aggregator();
aggregator.Visit(expr);
if (aggregator.Source is DomainExpression)
{
return ProjectionFromAggregation(aggregator);
}
else
{
var source = Visit(aggregator.Source);
var projector = aggregator.Projector;
if (projector != null)
{
return Expression.Call(
typeof(Enumerable).GetMethod("Select", new []{ typeof(IEnumerable<>), typeof(Func<,>) }).MakeGenericMethod(source.Type, projector.Type),
source,
projector);
}
else
{
return source;
}
}
}