Added TransformerLoader service

Author: WalterWoshid

src/CodeTransformerKernel.php

@@ -4,6 +4,7 @@
 
 use Okapi\CodeTransformer\Exception\Kernel\DirectKernelInitializationException;
 use Okapi\CodeTransformer\Service\Options;
+use Okapi\CodeTransformer\Service\TransformerLoader;
 use Okapi\Singleton\Singleton;
 
 /**
@@ -56,6 +57,8 @@ public static function init(
                 debug:         $debug,
             );
 
+            TransformerLoader::addTransformers($instance->transformers);
+
             $instance->registerServices();
         }
 
@@ -71,6 +74,9 @@ protected function registerServices(): void
     {
         // Options provider
         Options::register();
+
+        // Load the user-defined transformers
+        TransformerLoader::register();
     }
 
     /**

src/Service/TransformerLoader.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace Okapi\CodeTransformer\Service;
+
+use Okapi\Singleton\Singleton;
+
+/**
+ * # Transformer Loader
+ *
+ * The `TransformerLoader` class is used to load the code transformers.
+ */
+class TransformerLoader implements ServiceInterface
+{
+    use Singleton;
+
+    /**
+     * The list of transformers.
+     *
+     * @var class-string<Transformer>[]
+     */
+    private array $transformers = [];
+
+    /**
+     * Add transformers.
+     *
+     * @param class-string<Transformer>[] $transformers
+     *
+     * @return void
+     */
+    public static function addTransformers(array $transformers): void
+    {
+        $instance = self::getInstance();
+
+        $instance->transformers = array_merge(
+            $instance->transformers,
+            $transformers,
+        );
+    }
+
+    /**
+     * Register the transformer loader.
+     *
+     * @return void
+     */
+    public static function register(): void
+    {
+        $instance = self::getInstance();
+        $instance->ensureNotAlreadyInitialized();
+
+        // TODO: Load the transformers
+
+        $instance->setInitialized();
+    }
+}