C# 2.0のコレクションクロージャメソッド

http://capsctrl.que.jp/kdmsnr/wiki/bliki/?CollectionClosureMethod

改めて書いてみると、なんかすごいムズムズする……

using System;
using System.Collections.Generic;
using System.Text;

namespace Closure
{
  class Employee
  {
    public bool IsManager
    {
      get {return true;}
    }

    public void doSomething()
    {
    }

    public Office office
    {
      get { return new Office(); }
    }
  }

  class Office
  {
  }

  class Business
  {
    public List<Employee> managers(List<Employee> emps)
    {
      return emps.FindAll(
        delegate(Employee e)
        {
          return e.IsManager;
        }
      );
    }

    public void Do(List<Employee> emps)
    {
      emps.ForEach(
        delegate(Employee e)
        {
          e.doSomething();
        }
      );
    }

    public List<Office> collect(List<Employee> emps)
    {
      return emps.ConvertAll<Office>(
        delegate(Employee e)
        {
          return e.office;
        }
      );
    }

    public bool allManagers(List<Employee> emps)
    {
      return emps.TrueForAll(
        delegate(Employee e)
        {
          return e.IsManager;
        }
      );
    }

    public bool noManagers(List<Employee> emps)
    {
      return !emps.Exists(
        delegate(Employee e)
        {
          return e.IsManager;
        }
      );
    }
  }
}