static void Main(string[] args)
{
System.Console.WriteLine("Task #4: implement monad in a nonfunctional language");
// perform 1 * 2 + 30
var monadId = IdentityMonad <int> .Return(1).BindM(x =>
IdentityMonad <int> .Return(x * 2).BindM(y =>
IdentityMonad <int> .Return(y + 30))
);
System.Console.WriteLine("IdentityMonad test result: {0}", monadId.Value);
System.Console.WriteLine("MaybeMonad test:");
// the container will be broken because: 10 - 8 - 3 < 0
// despite 10 - 8 - 3 + 3 > 0
var container = new Container(10);
new int [] { 10, -8, -3, 3 }.Aggregate(container,
(c, x) => {
c.change(x);
System.Console.WriteLine(c);
return(c);
});
// nothing wrong in the following example
container = new Container(10);
new int [] { 10, -8, 3, -3 }.Aggregate(container,
(c, x) => {
c.change(x);
System.Console.WriteLine(c);
return(c);
});
}
public IdentityMonad <TTo> BindM <TTo>(Func <T, IdentityMonad <TTo> > f)
{
var mNew = f(Value) as IdentityMonad <TTo>;
return(IdentityMonad <TTo> .Return(mNew.Value));
}