using System;

using Monad;

​

public static class MaybeExtensions {

    public static Option<T> ToMaybe<T>(this T value) {

        return Option.Return(() => value);

    }

}

​

public static class EitherExtensions {

    public static Either<L, R> ToEitherOrFailWith<L, R>(this R value, Predicate<R> predicate, L orElse) {

        if (!predicate(value)) return Either.Left<L, R>(() => orElse);

        return Either.Right<L, R>(() => value);

    }

    public static Either<L, R> ToEither<L, R>(this R value) {

        return Either.Right<L, R>(() => value);

    }

}

​

public class Program

{

    public static void Main()

    {   

        var esum = (

            from x in 60.ToEither<string, int>()

            from y in 10.ToEitherOrFailWith(n => n > 0, "Cannot divide by Zero")

            select x / y

        ).Match(

            Right: r => r.ToString(),

            Left: l => l

        )();

        Console.WriteLine(esum);

    }

}

​