Make isEmpty a getter.

pkg/dartdoc/bin/dartdoc.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.
 
 /**
  * To generate docs for a library, run this script with the path to an
  * entrypoint .dart file, like:
  *
  *     $ dart dartdoc.dart foo.dart
  *
@@ skipping 108 matching lines @@
         }
       });
 
   argParser.addOption('include-lib',
       help: 'Use this option to explicitly specify which\n'
         'libraries to include in the documentation. If\n'
         'omitted, all used libraries are included by\n'
         'default. Specify a comma-separated list of\n'
         'library names, or call this option multiple times.',
       callback: (incLibs) {
-        if(!incLibs.isEmpty()) {
+        if(!incLibs.isEmpty) {
           List<String> allLibs = new List<String>();
           for(final lst in incLibs) {
             var someLibs = lst.split(',');
             for(final lib in someLibs) {
               allLibs.add(lib);
             }
           }
           dartdoc.excludedLibraries = allLibs;
         }
       }, allowMultiple: true);
 
   argParser.addOption('exclude-lib',
       help: 'Use this option to explicitly specify which\n'
         'libraries to exclude from the documentation. If\n'
         'omitted, no libraries are excluded. Specify a\n'
         'comma-separated list of library names, or call\n'
         'this option multiple times.',
       callback: (excLibs) {
-        if(!excLibs.isEmpty()) {
+        if(!excLibs.isEmpty) {
           List<String> allLibs = new List<String>();
           for(final lst in excLibs) {
             var someLibs = lst.split(',');
             for(final lib in someLibs) {
               allLibs.add(lib);
             }
           }
           dartdoc.excludedLibraries = allLibs;
         }
       }, allowMultiple: true);
 
   argParser.addOption('pkg',
       help: 'Sets the package directory to the specified directory.\n'
         'If omitted the package directory is the SDK pkg/ dir',
       callback: (pkgDir) {
         if(pkgDir != null) {
           pkgPath = new Path.fromNative(pkgDir);
         }
       });
 
   dartdoc.dartdocPath = libPath.append('pkg/dartdoc');
 
-  if (args.isEmpty()) {
+  if (args.isEmpty) {
     print('No arguments provided.');
     print(USAGE);
     print(argParser.getUsage());
     return;
   }
 
   final entrypoints = <Path>[];
   try {
     final option = argParser.parse(args);
     for(final arg in option.rest) {
       entrypoints.add(new Path.fromNative(arg));
     }
   } on FormatException catch (e) {
     print(e.message);
     print(USAGE);
     print(argParser.getUsage());
     return;
   }
 
-  if (entrypoints.isEmpty()) {
+  if (entrypoints.isEmpty) {
     print('No entrypoints provided.');
     print(argParser.getUsage());
     return;
   }
 
   cleanOutputDirectory(dartdoc.outputDir);
 
   dartdoc.documentLibraries(entrypoints, libPath, pkgPath);
 
   Future compiled = compileScript(dartdoc.mode, dartdoc.outputDir, libPath);
   Future filesCopied = copyDirectory(scriptDir.append('../static'),
                                      dartdoc.outputDir);
 
   Futures.wait([compiled, filesCopied]).then((_) {
     dartdoc.cleanup();
     print('Documented ${dartdoc.totalLibraries} libraries, '
           '${dartdoc.totalTypes} types, and ${dartdoc.totalMembers} members.');
   });
 }