Implement Mirror.isSubclassOf.

sdk/lib/_internal/lib/js_mirrors.dart

Index: sdk/lib/_internal/lib/js_mirrors.dart
diff --git a/sdk/lib/_internal/lib/js_mirrors.dart b/sdk/lib/_internal/lib/js_mirrors.dart
index b790ca9dac00bc652ffc088cd0740bb1f046adcb..da6ee8c553bf8fa74520e1caaae84d5b841e7b86 100644
--- a/sdk/lib/_internal/lib/js_mirrors.dart
+++ b/sdk/lib/_internal/lib/js_mirrors.dart
@@ -796,8 +796,12 @@ class JsMixinApplication extends JsTypeMirror with JsObjectMirror
 
   bool get isAbstract => throw new UnimplementedError();
 
-  bool isSubclassOf(ClassMirror other) => throw new UnimplementedError();
+  bool isSubclassOf(ClassMirror other) {
+    superclass.isSubclassOf(other) || mixin.isSubclassOf(other);
+  }
+
   bool isSubtypeOf(TypeMirror other) => throw new UnimplementedError();
+
   bool isAssignableTo(TypeMirror other) => throw new UnimplementedError();
 }
 
@@ -1148,6 +1152,15 @@ class JsTypeBoundClassMirror extends JsDeclarationMirror
         super(originalDeclaration.simpleName);
 
   String get _prettyName => 'ClassMirror';
+
+  String toString() {
+    String result = '$_prettyName on ${n(simpleName)}';
+    if (typeArguments != null) {
+      result = "$result<${typeArguments.join(', ')}>";
+    }
+    return result;
+  }
+
   String get _mangledName {
     for (TypeMirror typeArgument in typeArguments) {
       if (typeArgument != JsMirrorSystem._dynamicType) {
@@ -1394,6 +1407,7 @@ class JsTypeBoundClassMirror extends JsDeclarationMirror
   Function operator [](Symbol name) => throw new UnimplementedError();
 
   bool isSubtypeOf(TypeMirror other) => throw new UnimplementedError();
+
   bool isAssignableTo(TypeMirror other) => throw new UnimplementedError();
 }
 
@@ -1906,7 +1920,20 @@ class JsClassMirror extends JsTypeMirror with JsObjectMirror
 
   bool get isAbstract => throw new UnimplementedError();
 
-  bool isSubclassOf(ClassMirror other) => throw new UnimplementedError();
+  bool isSubclassOf(JsClassMirror other) {
+    if (other is! ClassMirror) {
+      throw new ArgumentError(other);
+    }
+    if (other is JsFunctionTypeMirror) {
+      return false;
+    } if (JS('bool', '# == #', other._jsConstructor, _jsConstructor)) {
+      return true;
+    } else if (superclass == null) {
+      return false;
+    } else {
+      return superclass.isSubclassOf(other);
+    }
+  }
 }
 
 class JsVariableMirror extends JsDeclarationMirror implements VariableMirror {
@@ -2503,8 +2530,10 @@ class JsFunctionTypeMirror extends BrokenClassMirror
     return _cachedToString = "$s'";
   }
 
-  bool isSubclassOf(ClassMirror other) => throw new UnimplementedError();
+  bool isSubclassOf(ClassMirror other) => false;

[Johnni Winther, 2014/02/26 15:44:59]

Should this return true on Function?

[karlklose, 2014/02/27 08:41:02]

I don't know, for me the predicate does not make sense on types.

It could, since we also implement JsTypeBoundMirror.isSubclassOf by going to the
class declaration. On the other hand, the VM returns false.

What is the usage scenario? Shouldn't the user rather use 'is
FunctionTypeMirror' to find out if a type is a function type?

[Johnni Winther, 2014/02/27 10:54:20]

Go with the VM.

+
   bool isSubtypeOf(TypeMirror other) => throw new UnimplementedError();
+
   bool isAssignableTo(TypeMirror other) => throw new UnimplementedError();
 
   // TODO(ahe): Implement this method.