stephenfrank/typedcollections

Collection classes for strict(ish) typing

TypedCollections

stephenfrank/typedcollections: "0.1.x", _(*1)

A collection of helper classes to enforce type safety in array collections., _(*2)

TypedCollection (base class)

The base class is array-accessible and enforces type-strictness by checking each item added to the collection against the defined type., _(*3)

The type can be defined through the constructor arguments or will be defined automatically based on the first item added., _(*4)

$integerCollection = new TypedCollection([1, 2]);
$integerCollection[] = 'a'; // throws InvalidArgumentException

{Type}Collection

Several classes have built-in types for strict checking against:, _(*5)

• bools BoolCollection
• integers IntegerCollection
• floats FloatCollection
• strings StringCollection
• array ArrayCollection
• objects ObjectCollection

$stringCollection = new StringCollection;
$stringCollection[] = 'foo';
$stringCollection[] = true; // throws InvalidArgumentException

ClassCollection

The ClassCollection will check that each item added to the array is of a particular class using get_class()., _(*6)

$foosCollection = new ClassCollection([new Foo]);
// or new ClassCollection([new Foo], 'Foo');
$stringCollection[] = new StdClass; // throws InvalidArgumentException

InstanceCollection

The InstanceCollection will check each item using instanceof so that collections can be defined by an interface or inherited class., _(*7)

$foosCollection = new InstanceCollection([
    new ArrayObject,
    new ArrayIterator
], 'ArrayAccess'); // This is A-okay

What’s the point?

Sometimes type strictness is important when exposing a public API in a framework or library. Effectively it reduces the number of places where the API consumer can shoot themselves in the foot., _(*8)

class NumberAdder
{
    public function sum(NumericCollection $numerics);
}

Sometimes when using a third-party/legacy library you might want type-check against the kind of garbage they return and raise an exception when they don't return clean data, _(*9)

$resources = new ClassCollection($thirdPartyThinger->getResources(), 'AcmeResource');
// Will explode if <Resource>[] is not returned

Lastly, InstanceCollection makes it super easy to create your own typed collections., _(*10)

class AcmeResourceCollection extends InstanceCollection
{
    protected $type = 'AcmeResource';
}