Make isEmpty a getter.

lib/compiler/implementation/patch_parser.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * This library contains the infrastructure to parse and integrate patch files.
  *
  * Three types of elements can be patched: [LibraryElement], [ClassElement],
  * [FunctionElement]. Patches are introduced in patch libraries which are loaded
  * together with the corresponding origin library. Which libraries that are
@@ skipping 163 matching lines @@
     // Parse [PartialClassElement] using a "patch"-aware parser instead
     // of calling its [parseNode] method.
     if (element.cachedNode != null) return;
 
     return measure(() => compiler.withCurrentElement(element, () {
       PatchMemberListener listener = new PatchMemberListener(compiler, element);
       Parser parser = new PatchClassElementParser(listener);
       Token token = parser.parseTopLevelDeclaration(element.beginToken);
       assert(identical(token, element.endToken.next));
       element.cachedNode = listener.popNode();
-      assert(listener.nodes.isEmpty());
+      assert(listener.nodes.isEmpty);
 
       Link<Element> patches = element.localMembers;
       applyContainerPatch(element.origin, patches);
     }));
   }
 
   void applyContainerPatch(ScopeContainerElement original,
                            Link<Element> patches) {
-    while (!patches.isEmpty()) {
+    while (!patches.isEmpty) {
       Element patchElement = patches.head;
       Element originalElement = original.localLookup(patchElement.name);
       if (patchElement.isAccessor() && originalElement != null) {
         if (!identical(originalElement.kind, ElementKind.ABSTRACT_FIELD)) {
           compiler.internalError(
               "Cannot patch non-getter/setter with getter/setter",
               element: originalElement);
         }
         AbstractFieldElement originalField = originalElement;
         if (patchElement.isGetter()) {
@@ skipping 10 matching lines @@
       } else {
         patchMember(originalElement, patchElement);
       }
       patches = patches.tail;
     }
   }
 
   bool isPatchElement(Element element) {
     // TODO(lrn): More checks needed if we introduce metadata for real.
     // In that case, it must have the identifier "native" as metadata.
-    for (Link link = element.metadata; !link.isEmpty(); link = link.tail) {
+    for (Link link = element.metadata; !link.isEmpty; link = link.tail) {
       if (link.head is PatchMetadataAnnotation) return true;
     }
     return false;
   }
 
   void patchMember(Element originalElement, Element patchElement) {
     // The original library has an element with the same name as the patch
     // library element.
     // In this case, the patch library element must be a function marked as
     // "patch" and it must have the same signature as the function it patches.
@@ skipping 261 matching lines @@
     super.addMember(element);
   }
 }
 
 // TODO(ahe): Get rid of this class.
 class PatchMetadataAnnotation extends MetadataAnnotation {
   final leg.Constant value = null;
 
   PatchMetadataAnnotation() : super(STATE_DONE);
 }