Merge pull request #45 from xp-framework/feature/package

Add `Reflection::package()` utility method

Author: thekid

src/main/php/lang/Reflection.class.php

@@ -2,7 +2,7 @@
 
 use lang\meta\{MetaInformation, FromSyntaxTree, FromAttributes};
 use lang\reflection\{Type, Package};
-use lang\{ClassLoader, ClassNotFoundException};
+use lang\{ClassLoader, ClassNotFoundException, IllegalArgumentException};
 
 /**
  * Factory for reflection instances.
@@ -56,6 +56,35 @@ public static function type($arg) {
     }
   }
 
+  /**
+   * Returns a reflection package for a given argument.
+   *
+   * @param  string|object|lang.XPClass|lang.reflection.Type|ReflectionClass $arg
+   * @return lang.reflection.Type
+   * @throws lang.IllegalArgumentException
+   */
+  public static function package($arg) {
+    if ($arg instanceof XPClass) {
+      return new Package($arg->getPackage()->getName());
+    } else if ($arg instanceof \ReflectionClass) {
+      return new Package($arg->getNamespaceName());
+    } else if ($arg instanceof Type) {
+      return $arg->package();
+    } else if (is_object($arg)) {
+      $class= get_class($arg);
+      return new Package(substr($class, 0, strrpos($class, '\\')));
+    } else {
+      $cl= ClassLoader::getDefault();
+      $name= strtr($arg, '\\', '.');
+      if ($cl->providesPackage($name)) {
+        return new Package($name);
+      } else if ($cl->providesClass($name)) {
+        return new Package(substr($name, 0, strrpos($name, '.')));
+      }
+      throw new IllegalArgumentException('No package named '.$name);
+    }
+  }
+
   /**
    * Creates a new reflection instance, which may either refer to a type
    * or to a package.

src/test/php/lang/reflection/unittest/ReflectionTest.class.php

@@ -19,6 +19,19 @@ private function arguments() {
     yield [new ReflectionObject($this), 'reflection object'];
   }
 
+  /** @return iterable */
+  private function packages() {
+    yield [__NAMESPACE__, 'namespace literal'];
+    yield ['lang.reflection.unittest', 'namespace name'];
+    yield [self::class, 'class literal'];
+    yield [nameof($this), 'class name'];
+    yield [$this, 'instance'];
+    yield [Type::forName(self::class), 'type'];
+    yield [Reflection::of(self::class), 'reflection'];
+    yield [new ReflectionClass($this), 'reflection class'];
+    yield [new ReflectionObject($this), 'reflection object'];
+  }
+
   #[Test, Values(from: 'arguments')]
   public function of($argument) {
     Assert::equals(nameof($this), Reflection::of($argument)->name());
@@ -29,6 +42,11 @@ public function type($argument) {
     Assert::equals(nameof($this), Reflection::type($argument)->name());
   }
 
+  #[Test, Values(from: 'packages')]
+  public function package($argument) {
+    Assert::equals(new Package('lang.reflection.unittest'), Reflection::package($argument));
+  }
+
   #[Test]
   public function of_package_name() {
     Assert::instance(Package::class, Reflection::of('lang.reflection.unittest'));