Get codebase ready for actually supporting versioning.

utils/pub/pub.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.
 
 /**
  * The main entrypoint for the pub command line application.
  */
 #library('pub');
 
-#import('yaml/yaml.dart');
+#import('io.dart');
+#import('pubspec.dart');
+#import('utils.dart');
+#import('version.dart');
 
-#import('io.dart');
-#import('utils.dart');
-
-#source('system_cache.dart');
-#source('packages_dir.dart');
 #source('command_list.dart');
 #source('command_install.dart');
 #source('command_update.dart');
 #source('command_version.dart');
+#source('git_source.dart');
 #source('package.dart');
+#source('packages_dir.dart');
+#source('sdk_source.dart');
 #source('source.dart');
 #source('source_registry.dart');
-#source('sdk_source.dart');
-#source('git_source.dart');
+#source('system_cache.dart');
+
+Version get pubVersion() => new Version(0, 0, 0);
 
 main() {
-  final args = new Options().arguments;
+  var args = new Options().arguments;
 
   // TODO(rnystrom): In addition to explicit "help" and "version" commands,
   // should also add special-case support for --help and --version arguments to
   // be consistent with other Unix apps.
-  final commands = {
+  var commands = {
     'list': new ListCommand(),
     'install': new InstallCommand(),
     'update': new UpdateCommand(),
     'version': new VersionCommand()
   };
 
   // TODO(rnystrom): Hack. This is temporary code to allow the pub tests to
   // pass in relevant paths. Eventually these should be either environment
   // variables or at least a cleaner arg parser.
   var cacheDir, sdkDir;
@@ skipping 21 matching lines @@
       printUsage(commands);
       return;
     }
 
     if (args[0] == '--version') {
       printVersion();
       return;
     }
   }
 
-  final cache = new SystemCache(cacheDir);
+  var cache = new SystemCache(cacheDir);
   cache.sources.register(new SdkSource(sdkDir));
   cache.sources.register(new GitSource());
   cache.sources.setDefault('sdk');
 
   // Select the command.
-  final command = commands[args[0]];
+  var command = commands[args[0]];
   if (command == null) {
     print('Unknown command "${args[0]}".');
     print('Run "pub help" to see available commands.');
     exit(64); // See http://www.freebsd.org/cgi/man.cgi?query=sysexits.
     return;
   }
 
   args.removeRange(0, 1);
   command.run(cache, args);
 }
 
 /** Displays usage information for the app. */
 void printUsage(Map<String, PubCommand> commands) {
   print('Pub is a package manager for Dart.');
   print('');
   print('Usage:');
   print('');
   print('  pub command [arguments]');
   print('');
   print('The commands are:');
   print('');
 
   // Show the commands sorted.
   // TODO(rnystrom): A sorted map would be nice.
   int length = 0;
-  final names = <String>[];
-  for (final command in commands.getKeys()) {
+  var names = <String>[];
+  for (var command in commands.getKeys()) {
     length = Math.max(length, command.length);
     names.add(command);
   }
 
   names.sort((a, b) => a.compareTo(b));
 
-  for (final name in names) {
+  for (var name in names) {
     print('  ${padRight(name, length)}   ${commands[name].description}');
   }
 
   print('');
   print('Use "pub help [command]" for more information about a command.');
 }
 
 void printVersion() {
-  print('Pub 0.0.0');
+  print('Pub $pubVersion');
 }
 
 class PubCommand {
   SystemCache cache;
-  PackagesDir packagesDir;
+
+  /**
+   * The package that pub was invoked from.
+   */
+  Package entrypoint;
 
   abstract String get description();
 
   void run(SystemCache cache_, List<String> args) {
     cache = cache_;
 
     // TODO(rnystrom): Each command should define the arguments it expects and
     // we can handle them generically here.
 
     // TODO(rnystrom): Will eventually need better logic to walk up
     // subdirectories until we hit one that looks package-like. For now, just
     // assume the cwd is it.
-    Package.load(workingDir, cache.sources).then((pkg) {
-      packagesDir = new PackagesDir(pkg, cache);
+    Package.load(workingDir, cache).then((package) {
+      entrypoint = package;
       onRun();
     });
   }
 
   abstract void onRun();
 }