Interfaces, casting, and is: Making classes keep their promises - refactoring
Head First C Sharp: A Learner’s Guide to Real-World Programming with C Sharp and .NET (Andrew Stellman(著)、Jennifer Greene(著)、O’Reilly Media)の Chapter 7(Interfaces, casting, and is: Making classes keep their promises)、p.371(Exercise)の解答を求めてみる。
コード
IWorker.cs
using System;
namespace ConsoleApp3;
public interface IWorker
{
public string Job { get; }
void WorkTheNextShift();
}
Bee.cs
using System;
namespace ConsoleApp3;
public abstract class Bee : IWorker
{
public string Job { get; private set; }
public virtual float CosntPerShift { get; }
public Bee(string job)
{
Job = job;
}
public void WorkTheNextShift()
{
if (HoneyVault.ConsumeHoney(CosntPerShift))
{
DoJob();
}
}
protected virtual void DoJob() { }
}
Queen.cs
using System;
namespace ConsoleApp3;
public class Queen : Bee
{
private const float EGGS_PER_SHIFT = 0.45f;
private const float HONEY_PER_UNASSIGNED_WORKER = 0.5f;
public string StatusReport { get; private set; } = "";
private IWorker[] workers = new Bee[0];
private float eggs = 0;
private float unassignedWorkers = 3;
public override float CosntPerShift => 2.15f;
protected override void DoJob()
{
eggs += EGGS_PER_SHIFT;
foreach (IWorker worker in workers)
{
worker.WorkTheNextShift();
}
HoneyVault.ConsumeHoney(HONEY_PER_UNASSIGNED_WORKER * workers.Length);
UpdateStatusReport();
}
public void AssignBee(string job)
{
switch (job)
{
case "Honey Manufacturer":
AddWorker(new HoneyManufacturer());
break;
case "Nectar Collector":
AddWorker(new NectarCollector());
break;
case "Egg Care":
AddWorker(new EggCare(this));
break;
}
UpdateStatusReport();
}
private void AddWorker(IWorker worker)
{
if (unassignedWorkers >= 1)
{
unassignedWorkers--;
Array.Resize(ref workers, workers.Length + 1);
workers[workers.Length - 1] = worker;
}
}
public void CareForEggs(float eggsToConvert)
{
if (eggs >= eggsToConvert)
{
eggs -= eggsToConvert;
unassignedWorkers += eggs;
}
}
private void UpdateStatusReport()
{
int nectarCollector = 0;
int honeyManufacturer = 0;
int eggCare = 0;
foreach (IWorker worker in workers)
{
switch (worker.Job)
{
case "Nectar Collector":
nectarCollector++;
break;
case "Honey Manufacturer":
honeyManufacturer++;
break;
case "Egg Care":
eggCare++;
break;
}
}
StatusReport = "Vault report:\n" +
HoneyVault.StatusReport + "\n" +
$"Egg count: {eggs}\n" +
$"Unassigned workers: {unassignedWorkers}\n" +
$"{nectarCollector} Nectar Collector bee";
if (nectarCollector > 1) StatusReport += "s";
StatusReport += $"\n{honeyManufacturer} Honey Manufacturer bee";
if (honeyManufacturer > 1) StatusReport += "s";
StatusReport += $"\n{eggCare} Egg Care bee";
if (eggCare > 1) StatusReport += "s";
StatusReport += $"\nTOTAL WORKERS: {workers.Length}";
}
public Queen() : base("Queen")
{
string[] jobs = ["Heny manufacturer", "Nectar Collectar", "Egg Care"];
foreach (string job in jobs)
{
AssignBee(job);
}
}
}