public static Cell<double> CapturePrice(
Stream<Fuel> sStart,
Cell<double> price1, Cell<double> price2,
Cell<double> price3)
{
Stream<double> sPrice1 = sStart.Snapshot(price1,
(f, p) => f == Fuel.One ? Maybe.Just(p) : Maybe.Nothing<double>()).FilterMaybe();
Stream<double> sPrice2 = sStart.Snapshot(price2,
(f, p) => f == Fuel.Two ? Maybe.Just(p) : Maybe.Nothing<double>()).FilterMaybe();
Stream<double> sPrice3 = sStart.Snapshot(price3,
(f, p) => f == Fuel.Three ? Maybe.Just(p) : Maybe.Nothing<double>()).FilterMaybe();
return sPrice1.OrElse(sPrice2.OrElse(sPrice3)).Hold(0.0);
}
public Keypad(Stream<Key> sKeypad, Stream<Unit> sClear)
{
CellLoop<int> value = new CellLoop<int>();
this.Value = value;
Stream<int> sKeyUpdate = sKeypad.Snapshot(value, (key, valueLocal) =>
{
if (key == Key.Clear)
{
return Maybe.Just(0);
}
int x10 = valueLocal * 10;
return x10 >= 1000
? Maybe.Nothing<int>()
: Maybe.Just(
key == Key.Zero ? x10 :
key == Key.One ? x10 + 1 :
key == Key.Two ? x10 + 2 :
key == Key.Three ? x10 + 3 :
key == Key.Four ? x10 + 4 :
key == Key.Five ? x10 + 5 :
key == Key.Six ? x10 + 6 :
key == Key.Seven ? x10 + 7 :
key == Key.Eight ? x10 + 8 :
x10 + 9);
}).FilterMaybe();
value.Loop(sKeyUpdate.OrElse(sClear.Map(u => 0)).Hold(0));
this.SBeep = sKeyUpdate.Map(_ => Unit.Value);
}
public static Cell<double> Accumulate(
Stream<Unit> sClearAccumulator,
Stream<int> sPulses,
Cell<double> calibration)
{
CellLoop<int> total = new CellLoop<int>();
total.Loop(sClearAccumulator.Map(u => 0)
.OrElse(sPulses.Snapshot(total, (pulsesLocal, totalLocal) => pulsesLocal + totalLocal))
.Hold(0));
return total.Lift(
calibration,
(totalLocal, calibrationLocal) => totalLocal * calibrationLocal);
}
private static Stream<End> WhenSetDown(Stream<UpDown> sNozzle, Fuel nozzleFuel, Cell<IMaybe<Fuel>> fillActive)
{
return sNozzle.Snapshot(fillActive, (u, f) => u == UpDown.Down && f.Equals(Maybe.Just(nozzleFuel)) ? Maybe.Just(End.Value) : Maybe.Nothing<End>()).FilterMaybe();
}
