public static INotifyLookup <TSource, TKey> ToLookup <TSource, TKey>(this INotifyEnumerable <TSource> source, Expression <Func <TSource, TKey> > keySelector)
{
var lookup = new IncrementalLookup <TSource, TKey>(source, keySelector);
lookup.Successors.SetDummy();
return(lookup);
}
private void PerformIncrementalLookup()
{
if (incremental == null)
{
incremental = new IncrementalLookup <TSource, TKey>(source.AsNotifiable(), keySelector);
incremental.Successors.SetDummy();
}
}
public INotifyEnumerable <TSource> AsNotifiable()
{
if (Incremental == null)
{
parent.PerformIncrementalLookup();
Incremental = parent.incremental.GetLookup(key);
}
return(Incremental);
}
