protected override IStream <Correlated <AggregationResult <TIn, TKey, TAggrRes> > > CreateOutputStream(AggregateCorrelatedArgs <TIn, TAggrRes, TKey> args)
{
return(CreateUnsortedStream(
args.InputStream.Observable.Aggregate(
i => new Correlated <TAggrRes>
{
Row = args.CreateEmptyAggregation(i.Row),
CorrelationKeys = new HashSet <Guid>()
},
i => args.GetKey(i.Row),
(a, i) =>
{
a.Row = args.Aggregate(a.Row, i.Row);
a.CorrelationKeys.UnionWith(i.CorrelationKeys);
return a;
},
(i, k, a) => new Correlated <AggregationResult <TIn, TKey, TAggrRes> >
{
CorrelationKeys = a.CorrelationKeys,
Row = new AggregationResult <TIn, TKey, TAggrRes>
{
Aggregation = a.Row,
FirstValue = i.Row,
Key = k
}
})));
}