CacheMap

Raxos\Collection\CacheMap is a final Map specialization that memoizes the result of a callable per key.

final class CacheMap extends Map

Methods

remember

public function remember(string $key, callable $fn): mixed

Returns the value at the key if it is already present. Otherwise it calls the callable, stores its result under the key, and returns it. The callable therefore runs at most once per key.

CacheMap inherits every method from Map, so get, set, has, unset, merge and toArray all remain available.

Example

<?php
declare(strict_types=1);

use Raxos\Collection\CacheMap;

$settings = new CacheMap();

$value = $settings->remember('theme', static function (): string {
    // Expensive lookup, runs only once for 'theme'.
    return loadThemeFromDisk();
});

// Subsequent calls return the stored value without calling the closure.
$again = $settings->remember('theme', static fn(): string => loadThemeFromDisk());

See also the maps concept page.