protected override void Main()
{
TraceLine(Instructions.PressAnyKeyToCancel);
var random = new Random();
IObservable <int> values = Observable
.Interval(TimeSpan.FromSeconds(1))
.Select(_ => random.Next(1, 50));
IConnectableObservable <StockTick> ticks = values
.Scan(StockTick.Empty, (acc, cur) => new StockTick(cur, cur - acc.Value))
.Publish();
IObservable <StockAlert> alerts = ticks.Parse(parser =>
from next in parser
let ups = next.Where(tick => tick.Change > 0)
let downs = next.Where(tick => tick.Change < 0)
let downAlert = from manyUps in ups.AtLeast(2).ToList()
from reversalDown in downs.NonGreedy()
where reversalDown.Change <= -11
select new StockAlert(manyUps, reversalDown)
let upAlert = from manyDowns in downs.AtLeast(2).ToList()
from reversalUp in ups.NonGreedy()
where reversalUp.Change >= 21
select new StockAlert(manyDowns, reversalUp)
select downAlert.Or(upAlert).Ambiguous(untilCount: 1));
using (ticks.Subscribe(WriteTick))
using (alerts.Subscribe(WriteAlert))
using (ticks.Connect())
{
WaitForKey();
}
}