static void Main(string[] args)
{
var stringOpt = Maybe <string> .Some("Hello, World");
Console.WriteLine($"The length of the given string is {stringOpt.Match(() => 0, _ => _.Length)}");
Console.WriteLine($"The length of the given string is {stringOpt.Map(_ => _.Length).Fold(0, (_, x) => x)}");
var lenOpt = from s in Maybe <string> .Some("Hello, World")
select s.Length;
Console.WriteLine($"The length of the given string is {lenOpt.GetOrElse(0)}");
var lenOpt2 = from s1 in Maybe <string> .None
select s1.Length;
Console.WriteLine($"The length of the given string is {lenOpt2.GetOrElse(0)}");
var userName1 = SingleValue <string> .Some("john");
var userName2 = SingleValue <string> .Some("john");
Console.WriteLine($"The two usernames are equal : {userName1 == userName2}");
((Maybe <string>)userName1).Match(() => null, _ => { Console.WriteLine("Call me Maybe!"); return(string.Empty); });
}