Adds AsColection::map() section

eloquent-mutators.md

@@ -449,6 +449,103 @@ protected function casts(): array
 }
 ```
 
+Collection items can be mapped into an specific class instance by using a second parameter. or the `map()` method if you want to use the base Collection class.
+
+```php
+use App\ValueObjects\Option;
+use Illuminate\Database\Eloquent\Casts\AsCollection;
+
+/**
+ * Get the attributes that should be cast.
+ *
+ * @return array<string, string>
+ */
+protected function casts(): array
+{
+    return [
+        'options' => AsCollection::map(Option::class)
+    ];
+}
+```
+
+For better control on how the items should be constructed once inside the Collection, you may set a callable that receives each item as an array.
+
+```php
+use App\ValueObjects\Option;
+use Illuminate\Database\Eloquent\Casts\AsCollection;
+
+/**
+ * Get the attributes that should be cast.
+ *
+ * @return array<string, string>
+ */
+protected function casts(): array
+{
+    return [
+        'options' => AsCollection::map([Option::class, 'fromArray']),
+    ];
+}
+```
+
+When handling a collection of objects, you should implement both `Illuminate\Contracts\Support\Arrayable` and `JsonSerializable` interfaces in the object class to control how these should be serialized into the database as JSON.
+
+```php
+<?php
+
+namespace App\ValueObjects;
+
+use Illuminate\Contracts\Support\Arrayable;
+use JsonSerilizable;
+
+class Option implements Arrayable, JsonSerializable
+{
+    /**
+     * Create a new Option instance.
+     */
+    public function __construct(
+        public string $name,
+        public mixed $value,
+        public bool $isLocked = false
+    ) {
+        //
+    }
+
+    /**
+     * Get the instance as an array.
+     *
+     * @return array{name: string, data: string, is_locked: bool}
+     */
+    public function toArray(): array
+    {
+        return [
+            'name' => $this->name,
+            'value' => $this->value,
+            'is_locked' => $this->isLocked,
+        ];
+    }
+
+    /**
+     * Specify data which should be serialized to JSON.
+     *
+     * @return array{name: string, data: string, is_locked: bool}
+     */
+    public function jsonSerialize(): array
+    {
+        return $this->toArray();
+    }
+
+    /**
+     * Create a new instance from an array.
+     *
+     * @param  array{name: string, data: string, is_locked: bool}  $data
+     */
+    public function fromArray(array $data): static
+    {
+        return new static($data['name'], $data['value'], $data['is_locked']);
+    }
+}
+```
+
 <a name="date-casting"></a>
 ### Date Casting