最酷的C#LINQ/Lambdas技巧你曾经拉过吗？

Question

最酷的C#LINQ/Lambdas技巧你曾经拉过吗？

cha*_*rit 42 c# linq lambda functional-programming

看到一篇关于C#中隐藏功能的帖子,但很多人都没有写过linq/lambdas的例子......所以......我想知道......

你见过/写过的C#LINQ和/或Lambdas /匿名代表的最酷(最优雅)是什么？

奖金,如果它也投入生产!

Answer 1

Mar*_*son 27

在LINQ光线跟踪肯定顶我的名单=)

我不太确定它是否优雅,但它肯定是我见过的最酷的linq表达式!

哦,只是非常清楚; 我并没有把它写(卢克·霍本一样)

让我想起 SQL 中的 Madlebrot：http://thedailywtf.com/Articles/Stupid-Coding-Tricks-The-TSQL-Madlebrot.aspx (2认同)

Answer 2

Chr*_*man 19

一些基本功能:

public static class Functionals
{
    // One-argument Y-Combinator.
    public static Func<T, TResult> Y<T, TResult>(Func<Func<T, TResult>, Func<T, TResult>> F)
    {
        return t => F(Y(F))(t);
    }

    // Two-argument Y-Combinator.
    public static Func<T1, T2, TResult> Y<T1, T2, TResult>(Func<Func<T1, T2, TResult>, Func<T1, T2, TResult>> F)
    {
        return (t1, t2) => F(Y(F))(t1, t2);
    }

    // Three-arugument Y-Combinator.
    public static Func<T1, T2, T3, TResult> Y<T1, T2, T3, TResult>(Func<Func<T1, T2, T3, TResult>, Func<T1, T2, T3, TResult>> F)
    {
        return (t1, t2, t3) => F(Y(F))(t1, t2, t3);
    }

    // Four-arugument Y-Combinator.
    public static Func<T1, T2, T3, T4, TResult> Y<T1, T2, T3, T4, TResult>(Func<Func<T1, T2, T3, T4, TResult>, Func<T1, T2, T3, T4, TResult>> F)
    {
        return (t1, t2, t3, t4) => F(Y(F))(t1, t2, t3, t4);
    }

    // Curry first argument
    public static Func<T1, Func<T2, TResult>> Curry<T1, T2, TResult>(Func<T1, T2, TResult> F)
    {
        return t1 => t2 => F(t1, t2);
    }

    // Curry second argument.
    public static Func<T2, Func<T1, TResult>> Curry2nd<T1, T2, TResult>(Func<T1, T2, TResult> F)
    {
        return t2 => t1 => F(t1, t2);
    }

    // Uncurry first argument.
    public static Func<T1, T2, TResult> Uncurry<T1, T2, TResult>(Func<T1, Func<T2, TResult>> F)
    {
        return (t1, t2) => F(t1)(t2);
    }

    // Uncurry second argument.
    public static Func<T1, T2, TResult> Uncurry2nd<T1, T2, TResult>(Func<T2, Func<T1, TResult>> F)
    {
        return (t1, t2) => F(t2)(t1);
    }
}

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如果您不知道如何使用它们,请不要做太多好事.为了了解这一点,您需要知道它们的用途: