ContainerInterface.php

<?php
/**
 * @license http://www.opensource.org/licenses/mit-license.php MIT (see the LICENSE file)
 */

namespace Interop\Container;

use Interop\Container\Exception\ContainerException;
use Interop\Container\Exception\NotFoundException;

/**
 * Describes the interface of a container that exposes methods to read its entries.
 */
interface ContainerInterface
{
    /**
     * Finds an entry of the container by its identifier and returns it.
     *
     * @param string $id Identifier of the entry to look for.
     *
     * @throws NotFoundException  No entry was found for this identifier.
     * @throws ContainerException Error while retrieving the entry.
     *
     * @return mixed Entry.
     */
    public function get(string $id);

    /**
     * Returns true if the container can return an entry for the given identifier.
     * Returns false otherwise.
     * 
     * `has($id)` returning true does not mean that `get($id)` will not throw an exception.
     * It does however mean that `get($id)` will not throw a `NotFoundException`.
     *
     * @param string $id Identifier of the entry to look for.
     *
     * @return boolean
     */
    public function has(string $id) : bool;
}