using System;

 // Functional Programming in C# with Categories 

 //https://leanpub.com/functional-programming-in-cSharp-with-categories

namespace CategoryTheoryWithCSharp.Lecture6_Functors

{

     public static partial class FunctionalExtensions

    {

         public static Func<T1> Select<T, T1>(this Func<T> @source, Func<T, T1> f)

        {

            return () => f(source());

        }

    }

    public class FunctorDemo 

    {

        public static void Main()

        {

            Func<int> factory = () => 2;

            Func<int> factoryAdd1 = from c in factory select c+3;

            var result = factoryAdd1();

            Console.WriteLine(result);

​

        }

​

    }

​

​

}