Execute any method, static or instance, as a callable

NamedCallable.php

<?php

namespace Acme;

class NamedCallable
{
    private $invoke;
    private $prefix;

    public function __construct(callable $invoke, callable $prefix)
    {
        $this->invoke = $invoke;
        $this->prefix = $prefix;
    }

    public function make($spec)
    {
        return function ($args) use ($spec) {
            $args = array_combine(
                // Prefix the keys of the args if required
                array_map($this->prefix, array_keys($args)),
                $args
            );

            // Invoke with spec and args
            return call_user_func($this->invoke, $spec, $args);
        };
    }
}

usage.php

<?php

require __DIR__ . '/../vendor/autoload.php';

class Hello
{
    public function user($name)
    {
        echo 'Hello, ', $name, '!';
    }
}

use Acme\NamedCallable;
use Auryn\Injector;

$injector = new Injector;

$invoke = [$injector, 'execute'];
$prefix = function ($key) {
    return ':' . $key;
};

$factory = new NamedCallable($invoke, $prefix);
$callable = $factory->make('Hello::user');

call_user_func($callable, ['name' => 'John']);

This is particularly useful with fast-route, which generates named parameters (as a hash) from route matching.