public async Task <IActionResult> GetOrderItems(int orderId)
{
var getOrderExpr =
from orderResult in RestaurantDomainEx.GetOrder(orderId)
select orderResult;
var order = await _interpreter.Interpret(getOrderExpr, Unit.Default);
var getOrderItemsExpr =
from orderItemsResult in RestaurantDomain.GetOrderItems(order.Order)
select orderItemsResult;
var orderItems = await _interpreter.Interpret(getOrderItemsExpr, Unit.Default);
return(orderItems.Match(
found => (IActionResult)Ok(found.OrderItems),
notFound => NotFound()));
}