maybe.md

Maybe

Usually we're thinking like that: "I have a $value, and I need to pass it to someFunction()". This container force us to swap our thoughts to: "I have a $value, and I need apply someFunction() to it". This allows us to encapsulate some logic inside container, like is_null checks.

if(!is_null($value)) {
    // do something with $value
}

Maybe helps you avoid code duplication like above. Maybe is a container for a value that could present or not (it's like a Schrödinger's box with the cat inside).

Let's imagine that you need took $article from repository, take only 22 characters from title, and make it caps.

class ArticlesRepository
{
    public function get(int $id): array|null
    {
        return $this->entityManager->get($id);
    }
}

$article = $repository->get(120);

$articleTitle = null;
if (!is_null($article)) {
    $articleTitle = strtoupper(substr($article['title'], 0, 22));
}

// use $articleTitle somewhere below

Now let's modify repository, so it will return one type Maybe.

class ArticlesRepository
{
    public function get(int $id): Maybe
    {
        return Maybe::of($this->entityManager->get($id));
    }
}

$articleTitle = $repository->get(120)->map(prop('title'))->map(take(22))->map('strtoupper');

// use $articleTitle somewhere below, you can call `$articleTitle->extract()` if you want to get value outside from container.

The point is that your methods and function return one type. Usually they return value or NULL, so it lead to additional IFs.

You may notice that Maybe can't tell what exactly happened. No entity in DB or it was connection issue? User Either if error is matter for you.