Add Collection datas tructure

composer.json

@@ -4,6 +4,7 @@
     "type": "library",
     "keywords": [
         "ArrayAccess",
+        "Collection",
         "Countable",
         "Getter",
         "Iterator",

src/DataStructures/Collection.php

@@ -0,0 +1,195 @@
+<?php
+
+/**
+ * PHP Basics
+ *
+ * Copyright (C) 2024 Sebastian Meyer <sebastian.meyer@opencultureconsulting.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace OCC\Basics\DataStructures;
+
+use ArrayAccess;
+use Countable;
+use IteratorAggregate;
+use OCC\Basics\InterfaceTraits\ArrayAccessTrait;
+use OCC\Basics\InterfaceTraits\CountableTrait;
+use OCC\Basics\InterfaceTraits\IteratorAggregateTrait;
+
+/**
+ * A generic collection of items.
+ *
+ * @author Sebastian Meyer <sebastian.meyer@opencultureconsulting.com>
+ * @package Basics\DataStructures
+ *
+ * @api
+ *
+ * @template Item of mixed
+ * @implements ArrayAccess<array-key, Item>
+ * @implements IteratorAggregate<Item>
+ */
+class Collection implements ArrayAccess, Countable, IteratorAggregate
+{
+    /** @use ArrayAccessTrait<Item> */
+    use ArrayAccessTrait;
+    /** @use CountableTrait<Item> */
+    use CountableTrait;
+    /** @use IteratorAggregateTrait<Item> */
+    use IteratorAggregateTrait;
+
+    /**
+     * Add an item to the collection.
+     *
+     * @param Item $item The new item
+     *
+     * @return void
+     *
+     * @api
+     */
+    public function add(mixed $item): void
+    {
+        $this->data[] = $item;
+    }
+
+    /**
+     * Clear the collection of any items.
+     *
+     * @return void
+     *
+     * @api
+     */
+    public function clear(): void
+    {
+        $this->data = [];
+    }
+
+    /**
+     * Get a new collection with the same set of items.
+     *
+     * @return Collection<Item> The new collection with the same items
+     *
+     * @api
+     */
+    public function copy(): Collection
+    {
+        return new Collection($this->data);
+    }
+
+    /**
+     * Get the item at the specified index.
+     *
+     * @param array-key $key The item's index
+     *
+     * @return ?Item The item or NULL if key is invalid
+     *
+     * @api
+     */
+    public function get(int|string $key): mixed
+    {
+        return $this->data[$key] ?? null;
+    }
+
+    /**
+     * Check if collection is empty.
+     *
+     * @return bool Whether the collection contains any items
+     *
+     * @api
+     */
+    public function isEmpty(): bool
+    {
+        return $this->count() === 0;
+    }
+
+    /**
+     * Remove an item from the collection.
+     *
+     * @param array-key $key The item's key
+     *
+     * @return void
+     *
+     * @api
+     */
+    public function remove(int|string $key): void
+    {
+        unset($this->data[$key]);
+    }
+
+    /**
+     * Set the item at the specified index.
+     *
+     * @param array-key $key The new item's index
+     * @param Item $item The new item
+     *
+     * @return void
+     *
+     * @api
+     */
+    public function set(int|string $key, mixed $item): void
+    {
+        $this->data[$key] = $item;
+    }
+
+    /**
+     * Return array representation of collection.
+     *
+     * @return array<Item> Array of collection items
+     *
+     * @api
+     */
+    public function toArray(): array
+    {
+        return $this->data;
+    }
+
+    /**
+     * Create a collection of items.
+     *
+     * @param array<Item> $items Initial set of items
+     *
+     * @return void
+     */
+    public function __construct(array $items = [])
+    {
+        $this->data = $items;
+    }
+
+    /**
+     * Magic method to read collection items as properties.
+     *
+     * @param array-key $key The item's index
+     *
+     * @return ?Item The item or NULL if key is invalid
+     */
+    public function __get(int|string $key): mixed
+    {
+        return $this->get($key);
+    }
+
+    /**
+     * Magic method to write collection items as properties.
+     *
+     * @param array-key $key The new item's index
+     * @param Item $item The new item
+     *
+     * @return void
+     */
+    public function __set(int|string $key, mixed $item): void
+    {
+        $this->set($key, $item);
+    }
+}