Does C# support function composition?

Question

In the latest version of C#, can I do something like Haskell's function composition? more...?

Function composition is the act of pipelining the result of one function, to the input of another, creating an entirely new function.

I feel like linq is the closest but that's chaining, not function composition, right?

Answer 1

public static class Extensions {     public static Func<T, TReturn2> Compose<T, TReturn1, TReturn2>(this Func<TReturn1, TReturn2> func1, Func<T, TReturn1> func2)     {         return x => func1(func2(x));     } } 

Usage:

Func<int, int> makeDouble = x => x * 2; Func<int, int> makeTriple = x => x * 3; Func<int, string> toString = x => x.ToString(); Func<int, string> makeTimesSixString = toString.Compose(makeDouble).Compose(makeTriple);  //Prints "true" Console.WriteLine(makeTimesSixString (3) == toString(makeDouble(makeTriple(3)))); 

Answer 2

I did not let the compiler check this, but this should be possible:

public static Func<T3,T1> my_chain<T1, T2, T3>(Func<T2,T1> f1, Func<T3,T2> f2) {     return x => f2(f1(x)); }