up: update some code syntax, update readme

Author: inhere

README.md

@@ -105,6 +105,8 @@ $loader->addClassMap([
 
 ### Optional
 
+它旨在消除过多的if判断
+
 Not use Optional:
 
 ```php
@@ -124,9 +126,20 @@ Use Optional:
 ```php
 use Toolkit\Stdlib\Util\Optional;
 
-$username = Optional::ofNullable($userModel)->map(function ($userModel) {
-    return $userModel->name;
-})->orElse('unknown');
+$username = Optional::ofNullable($userModel)
+    ->map(function ($userModel) {
+        return $userModel->name;
+    })->orElse('unknown');
+```
+
+Use arrow syntax:
+
+```php
+use Toolkit\Stdlib\Util\Optional;
+
+$username = Optional::ofNullable($userModel)
+    ->map(fn($userModel) => $userModel->name)
+    ->orElse('unknown');
 ```
 
 ### PhpDotEnv

src/Util/Optional.php

@@ -6,7 +6,6 @@
 use RuntimeException;
 use Throwable;
 use Toolkit\Stdlib\Helper\Valid;
-use Toolkit\Stdlib\Obj;
 use Toolkit\Stdlib\Util\Stream\DataStream;
 use UnexpectedValueException;
 use function gettype;

src/Util/Pipeline.php

@@ -37,9 +37,7 @@ public function __construct()
     public function add(callable $stage): PipelineInterface
     {
         if ($stage instanceof $this) {
-            $stage->add(function ($payload) {
-                return $this->invokeStage($payload);
-            });
+            $stage->add(fn($payload) => $this->invokeStage($payload));
         }
 
         $this->stages->attach($stage);
@@ -49,7 +47,7 @@ public function add(callable $stage): PipelineInterface
     /**
      * {@inheritdoc}
      */
-    public function run(mixed $payload)
+    public function run(mixed $payload): mixed
     {
         $this->stages->rewind();
 
@@ -59,12 +57,17 @@ public function run(mixed $payload)
     /**
      * {@inheritdoc}
      */
-    public function __invoke(mixed $payload)
+    public function __invoke(mixed $payload): mixed
     {
         return $this->run($payload);
     }
 
-    private function invokeStage($payload)
+    /**
+     * @param mixed $payload
+     *
+     * @return mixed
+     */
+    private function invokeStage(mixed $payload): mixed
     {
         $stage = $this->stages->current();
         $this->stages->next();

test/Util/OptionalTest.php

@@ -23,6 +23,10 @@ public function testOptionalBasic(): void
         })->orElse(25);
 
         $this->assertEquals(25, $val);
+
+        // use arrow syntax:
+        $val = $o->filter(fn($val) => $val > 25)->orElse(25);
+        $this->assertEquals(25, $val);
     }
 
     public function testOptional_or(): void
@@ -36,7 +40,10 @@ public function testOptional_or(): void
         $val = $o->or(function () {
             return Optional::of(23);
         })->get();
+        $this->assertEquals(23, $val);
 
+        // use arrow syntax:
+        $val = $o->or(fn() => Optional::of(23))->get();
         $this->assertEquals(23, $val);
     }
 }