<?php

require("vendor/autoload.php");

use TypedPHP\Optional\Optional;

class Foo
{
    public function hello()
    {
        return new Bar();
    }
}

class Bar
{
    public function world()
    {
        return "hello world";
    }
}

$optional = new Optional(new Foo());
$optional->hello()->world()->value(); // "hello world"

<?php

require("vendor/autoload.php");

use TypedPHP\Optional\None;

$none = new None();
$none->hello()->world()->value(); // null

<?php

require("vendor/autoload.php");

use TypedPHP\Optional\None;

$none = new None();
$none
    ->none(function() { print "none"; }); // "none" printed
    ->value(function($value) { print $value; }); // $value not printed

use TypedPHP\Optional\Optional;

$optional = new Optional("hello world");
$optional
    ->none(function() { print "none"; }); // "none" not printed
    ->value(function($value) { print $value; }); // "hello world" printed