Improved PHP type system in userland

This package is a mere proof of concept about what's possible in PHP's userland to improve type checking. It adds support for typed lists, tuples, structs, and generics. Because all is done in userland, there are limitations on what syntax is possible.

Installation

You can install the package via composer:

composer require spatie/typed

Usage

Typed lists and collections:

$list = new IntegerList([1, 4]);

$list[] = 'a'; // TypeError

$list = new Collection(T::bool(), [true, false]);

$list[] = new Post(); // TypeError

Generics:

$postList = new Collection(T::generic(Post::class));

$postList = 1; // TypeError

Tuples:

$point = new Tuple(T::float(), T::float());

$point[0] = 1.5;
$point[1] = 3;

$point[0] = 'a'; // TypeError
$point['a'] = 1; // TypeError
$point[10] = 1; // TypeError

Structs:

$developer = new Struct([
    'name' => T::string(),
    'age' => T::int(),
]);

$developer['name'] = 'Brent';

$developer->set([
    'name' => 'BrenDt',
    'age' => 23,
]);

echo $developer->age;

$developer->name = 'Brent';

$developer->age = 'abc' // TypeError
$developer->somethingElse = 'abc' // TypeError

What's not included:

Proper syntax.
IDE auto completion for generic types.
Prevention of type casting between scalar types.
Nullable types, though I could add it.
Type hint generics in functions.

Why did we build this?

PHP has a very weak type system. This is simultaneously a strength and a weakness. Weak type systems offer a very flexible development platform, while strong type systems can prevent certain bugs from happening at runtime.

In its current state, PHP's type system isn't ready for some of the features many want. Take, for example, a look at some RFC's proposing changes to the current type system.

Generics: https://wiki.php.net/rfc/generics
Typed properties: https://wiki.php.net/rfc/typed-properties
Readonly properties: https://wiki.php.net/rfc/readonly_properties

Some of those are already declined because of runtime performance issues, or implementation difficulties. This package is a thought experiment of what we could do if those features are implemented in PHP, usable with native syntax.

For example, the following syntax would be much more preferable over how this package does it.

$postList = new Collection<Post>();

// vs.

$postList = new Collection(T::generic(Post::class));

Anyways, it's stuff to think about. And maybe PHP's type system is fine as it is now? You can read more about type safety on my blog.

Contributing

Please see CONTRIBUTING for details.

Security

If you discover any security related issues, please email freek@spatie.be instead of using the issue tracker.

Postcardware

You're free to use this package, but if it makes it to your production environment we highly appreciate you sending us a postcard from your hometown, mentioning which of our package(s) you are using.

Our address is: Spatie, Samberstraat 69D, 2060 Antwerp, Belgium.

We publish all received postcards on our company website.

Credits

Support us

Spatie is a webdesign agency based in Antwerp, Belgium. You'll find an overview of all our open source projects on our website.

Does your business depend on our contributions? Reach out and support us on Patreon. All pledges will be dedicated to allocating workforce on maintenance and new awesome stuff.

License

The MIT License (MIT). Please see License File for more information.

Furgas / typed