Weak Types

The Weak Types component provides a set of classes for working with weak references in PHP. It allows you to store objects without preventing them from being garbage collected, and react to their destruction.

Installation

Requirements:

PHP ^8.4

Usage

ObservableWeakSet

ObservableWeakSet allows you to store a set of objects and track their destruction. It's useful when you need to maintain a collection of objects and react when they are garbage collected.

use Boson\Component\WeakType\ObservableWeakSet;

// Create a new observable weak set
$set = new ObservableWeakSet();

// Watch an object
$set->watch($object, function (object $ref): void {
    echo "Object has been destroyed, cleaning up resources...\n";
});

// Iterate over all entries
foreach ($set as $object) {
    // Process each object
}

// Get the number of entries
$count = count($set);

ObservableWeakMap

ObservableWeakMap allows you to store a set of objects with referenced values and track their destruction. It's useful when you need to maintain a mapping between objects and react when they are garbage collected.

use Boson\Component\WeakType\ObservableWeakMap;

// Create a new observable weak map
$map = new ObservableWeakMap();

// Watch an object and its associated value
$map->watch($keyObject, $refObject, function (object $ref): void {
    echo "Object has been destroyed, cleaning up resources...\n";
});

// Find a value by key
$value = $map->find($keyObject);

// Iterate over all entries
foreach ($map as $keyObject => $refObject) {
    // Process each entry
}

// Get the number of entries
$count = count($map);

13 June 2025