发一个lambda表达式的例子,一直没有看懂。
delegate T SelfApplicable<T>(SelfApplicable<T> self);
/// <summary>
/// Lambda 表达式 递归测试
/// </summary>
/// <param name="i"></param>
/// <returns></returns>
public int Test2(int i)
{
// Y 算子
SelfApplicable<Func<Func<Func<int, int>, Func<int, int>>, Func<int, int>>> Y = y => f => x => f(y(y)(f))(x);
// 不动点
Func<Func<Func<int, int>, Func<int, int>>, Func<int, int>> Fix = Y(Y);
// 高阶函数定义
Func<Func<int, int>, Func<int, int>> F = fac => x => x == 0 ? 1 : x * fac(x - 1);
// 阶乘函数
Func<int, int> factorial = Fix(F);
int r = factorial(i);
Console.WriteLine("{0}的阶乘={1}",i,r);
return r;
}
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感觉lambda表达式很强大啊,但是一直没有看懂