Add support for the global package

src/main/php/lang/reflection/Package.class.php

@@ -21,6 +21,9 @@ public function __construct(... $components) {
     $this->name= rtrim(strtr(implode('.', $components), '\\', '.'), '.');
   }
 
+  /** Returns whether this is the global package */
+  public function global(): bool { return '' === $this->name; }
+
   /** Returns this package's name (in dotted form) */
   public function name(): string { return $this->name; }
 
@@ -39,13 +42,16 @@ public function classLoaders() {
   }
 
   /**
-   * Returns this package's parent, if any
+   * Returns this package's parent. Returns NULL if this package refers to the
+   * global package.
    *
    * @return ?self
    */
   public function parent() {
+    if ('' === $this->name) return null;
+
     $p= strrpos($this->name, '.');
-    return false === $p ? null : new Package(substr($this->name, 0, $p));
+    return false === $p ? new Package() : new Package(substr($this->name, 0, $p));
   }
 
   /**
@@ -54,7 +60,7 @@ public function parent() {
    * @return iterable
    */
   public function children() {
-    $base= $this->name.'.';
+    $base= $this->name ? $this->name.'.' : '';
     $loader= ClassLoader::getDefault();
     foreach ($loader->packageContents($this->name) as $entry) {
       if ('/' === $entry[strlen($entry) - 1]) {
@@ -70,7 +76,7 @@ public function children() {
    */
   public function types() {
     $ext= strlen(\xp::CLASS_FILE_EXT);
-    $base= $this->name.'.';
+    $base= $this->name ? $this->name.'.' : '';
     $loader= ClassLoader::getDefault();
     foreach ($loader->packageContents($this->name) as $entry) {
       if (0 === substr_compare($entry, \xp::CLASS_FILE_EXT, -$ext)) {
@@ -87,15 +93,17 @@ public function types() {
    * @throws lang.IllegalArgumentException
    */
   public function type($name) {
+    if ('' === $this->name) return Reflection::type($name);
+
+    // Compare type package and this package
     $type= strtr($name, '\\', '.');
     $p= strrpos($type, '.');
-
     if (false === $p) {
-      return Reflection::of($this->name.'.'.$type);
+      return Reflection::type($this->name.'.'.$type);
     } else if (0 === strncmp($this->name, $type, $p)) {
-      return Reflection::of($type);
-    } else {
-      throw new IllegalArgumentException('Given type '.$type.' is not in package '.$this->name);
+      return Reflection::type($type);
     }
+
+    throw new IllegalArgumentException('Given type '.$type.' is not in package '.$this->name);
   }
 }

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

@@ -11,6 +11,21 @@ public function name($arg) {
     Assert::equals('lang.reflection', (new Package($arg))->name());
   }
 
+  #[Test]
+  public function global() {
+    Assert::true((new Package())->global());
+  }
+
+  #[Test, Values(['lang', 'lang.reflection', 'lang.reflect.unittest'])]
+  public function leveled($package) {
+    Assert::false((new Package($package))->global());
+  }
+
+  #[Test]
+  public function global_name() {
+    Assert::equals('', (new Package())->name());
+  }
+
   #[Test]
   public function create_via_components() {
     Assert::equals('lang.reflection.unittest', (new Package('lang', 'reflection', 'unittest'))->name());
@@ -26,6 +41,16 @@ public function parent() {
     Assert::equals(new Package('lang'), (new Package('lang.reflection'))->parent());
   }
 
+  #[Test]
+  public function parent_of_toplevel() {
+    Assert::equals(new Package(), (new Package('lang'))->parent());
+  }
+
+  #[Test]
+  public function global_package_has_no_parent() {
+    Assert::null((new Package())->parent());
+  }
+
   #[Test]
   public function children() {
     Assert::equals(