Scala っぽいやつ

Scala.cs

public static class Scala
{
    public static Func<T, V> Compose<T, U, V>(this Func<U, V> first, Func<T, U> second)
    {
        if (first == null) throw new ArgumentNullException("first");
        if (second == null) throw new ArgumentNullException("second");

        return t => first(second(t));
    }

    public static Func<T, V> AndThen<T, U, V>(this Func<T, U> first, Func<U, V> second)
    {
        if (first == null) throw new ArgumentNullException("first");
        if (second == null) throw new ArgumentNullException("second");

        return t => second(first(t));
    }
}