Add ArrayAccess support of the DocBlock object

Author: Kirill Nesmeyanov

src/DocBlock.php

@@ -10,9 +10,13 @@
 use TypeLang\PHPDoc\Tag\TagProviderInterface;
 
 /**
- * @template-implements \IteratorAggregate<array-key, Tag>
+ * @template-implements \IteratorAggregate<int<0, max>, Tag>
+ * @template-implements \ArrayAccess<int<0, max>, Tag|null>
  */
-final class DocBlock implements TagProviderInterface, \IteratorAggregate
+final class DocBlock implements
+    TagProviderInterface,
+    \IteratorAggregate,
+    \ArrayAccess
 {
     use TagProvider;
 
@@ -26,6 +30,26 @@ public function __construct(
         $this->bootTagProvider($tags);
     }
 
+    public function offsetExists(mixed $offset): bool
+    {
+        return isset($this->tags[$offset]);
+    }
+
+    public function offsetGet(mixed $offset): ?Tag
+    {
+        return $this->tags[$offset] ?? null;
+    }
+
+    public function offsetSet(mixed $offset, mixed $value): void
+    {
+        throw new \BadMethodCallException(self::class . ' objects are immutable');
+    }
+
+    public function offsetUnset(mixed $offset): void
+    {
+        throw new \BadMethodCallException(self::class . ' objects are immutable');
+    }
+
     public function getDescription(): Description
     {
         return $this->description;