Software that pivots ideas into shipped products.

public final class InventoryService {
  public StockReport reconcile(List<Movement> moves) {
    int received = moves.stream()
      .filter(Movement::isInbound)
      .mapToInt(Movement::quantity)
      .sum();

    int shipped = moves.stream()
      .filter(Movement::isOutbound)
      .mapToInt(Movement::quantity)
      .sum();

    return new StockReport(received, shipped, received - shipped);
  }
}