Make isEmpty a getter.

lib/compiler/implementation/dart_backend/backend.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.
 
 class ElementAst {
   final Node ast;
   final TreeElements treeElements;
 
   ElementAst(this.ast, this.treeElements);
 
@@ skipping 67 matching lines @@
             return true;
           }
         }
       }
       return false;
     }
 
     rewiteStatement(Statement statement) {
       if (statement is Block) {
         Link statements = statement.statements.nodes;
-        if (!statements.isEmpty() && statements.tail.isEmpty()) {
+        if (!statements.isEmpty && statements.tail.isEmpty) {
           Statement single = statements.head;
           bool isDeclaration =
               single is VariableDefinitions || single is FunctionDeclaration;
           if (!isDeclaration) return single;
         }
       }
       return statement;
     }
 
     NodeList statements = block.statements;
@@ skipping 48 matching lines @@
         }
         if (typeArgument == null) continue;
         assert(typeArgument is TypeAnnotation);
         DartType argumentType =
             compiler.resolveTypeAnnotation(classElement, typeArgument);
         assert(argumentType != null);
         workQueue.add(argumentType);
       }
     }
 
-    while (!workQueue.isEmpty()) {
+    while (!workQueue.isEmpty) {
       DartType type = workQueue.removeLast();
       if (processedTypes.contains(type)) continue;
       processedTypes.add(type);
       if (type is TypedefType) return false;
       if (type is InterfaceType) {
         ClassElement element = type.element;
         ClassNode node = element.parseNode(compiler);
         // Check class type args.
         processTypeArguments(element, node.typeParameters);
         // Check superclass type args.
@@ skipping 168 matching lines @@
     // but which originally had any constructor.  That should prevent
     // those classes from being instantiable with default constructor.
     Identifier synthesizedIdentifier =
         new Identifier(new StringToken(IDENTIFIER_INFO, '', -1));
 
     NextClassElement:
     for (ClassElement classElement in classMembers.getKeys()) {
       for (Element member in classMembers[classElement]) {
         if (member.isConstructor()) continue NextClassElement;
       }
-      if (classElement.constructors.isEmpty()) continue NextClassElement;
+      if (classElement.constructors.isEmpty) continue NextClassElement;
 
       // TODO(antonm): check with AAR team if there is better approach.
       // As an idea: provide template as a Dart code---class C { C.name(); }---
       // and then overwrite necessary parts.
       SynthesizedConstructorElement constructor =
           new SynthesizedConstructorElement(classElement);
       constructor.type = new FunctionType(
           compiler.types.voidType, const Link<DartType>(),
           constructor);
       constructor.cachedNode = new FunctionExpression(
@@ skipping 179 matching lines @@
 }
 
 compareElements(e0, e1) {
   int result = compareBy((e) => e.getLibrary().uri.toString())(e0, e1);
   if (result != 0) return result;
   return compareBy((e) => e.position().charOffset)(e0, e1);
 }
 
 List<Element> sortElements(Collection<Element> elements) =>
     sorted(elements, compareElements);