Create a "PackageRef" class that defines a versionless package reference.

sdk/lib/_internal/pub/lib/src/pubspec.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.
 
 library pubspec;
 
 import 'package:yaml/yaml.dart';
 import 'package:pathos/path.dart' as path;
 
 import 'io.dart';
 import 'package.dart';
 import 'source.dart';
 import 'source_registry.dart';
 import 'utils.dart';
 import 'version.dart';
 
 /// The parsed and validated contents of a pubspec file.
 class Pubspec {
   /// This package's name.
   final String name;
 
   /// This package's version.
   final Version version;
 
   /// The packages this package depends on.
-  final List<PackageRef> dependencies;
+  final List<PackageDep> dependencies;
 
   /// The packages this package depends on when it is the root package.
-  final List<PackageRef> devDependencies;
+  final List<PackageDep> devDependencies;
 
   /// The environment-related metadata.
   final PubspecEnvironment environment;
 
   /// All pubspec fields. This includes the fields from which other properties
   /// are derived.
   final Map<String, Object> fields;
 
   /// Loads the pubspec for a package [name] located in [packageDir].
   factory Pubspec.load(String name, String packageDir, SourceRegistry sources) {
@@ skipping 18 matching lines @@
     }
   }
 
   Pubspec(this.name, this.version, this.dependencies, this.devDependencies,
           this.environment, [Map<String, Object> fields])
     : this.fields = fields == null ? {} : fields;
 
   Pubspec.empty()
     : name = null,
       version = Version.none,
-      dependencies = <PackageRef>[],
-      devDependencies = <PackageRef>[],
+      dependencies = <PackageDep>[],
+      devDependencies = <PackageDep>[],
       environment = new PubspecEnvironment(),
       fields = {};
 
   /// Whether or not the pubspec has no contents.
   bool get isEmpty =>
     name == null && version == Version.none && dependencies.isEmpty;
 
   // TODO(rnystrom): Instead of allowing a null argument here, split this up
   // into load(), parse(), and _parse() like LockFile does.
   /// Parses the pubspec stored at [filePath] whose text is [contents]. If the
@@ skipping 146 matching lines @@
   }
 
   var goodScheme = new RegExp(r'^https?:');
   if (!goodScheme.hasMatch(url)) {
     throw new FormatException(
         'The "$field" field should be an "http:" or "https:" URL, but '
         'was "$url".');
   }
 }
 
-List<PackageRef> _parseDependencies(String pubspecPath, SourceRegistry sources,
+List<PackageDep> _parseDependencies(String pubspecPath, SourceRegistry sources,
     yaml) {
-  var dependencies = <PackageRef>[];
+  var dependencies = <PackageDep>[];
 
   // Allow an empty dependencies key.
   if (yaml == null) return dependencies;
 
   if (yaml is! Map || yaml.keys.any((e) => e is! String)) {
     throw new FormatException(
         'The pubspec dependencies should be a map of package names, but '
         'was ${yaml}.');
   }
 
@@ skipping 27 matching lines @@
       source = sources[sourceName];
       description = spec[sourceName];
     } else {
       throw new FormatException(
           'Dependency specification $spec should be a string or a mapping.');
     }
 
     description = source.parseDescription(pubspecPath, description,
         fromLockFile: false);
 
-    dependencies.add(new PackageRef(
+    dependencies.add(new PackageDep(
         name, source, versionConstraint, description));
   });
 
   return dependencies;
 }
 
 /// The environment-related metadata in the pubspec. Corresponds to the data
 /// under the "environment:" key in the pubspec.
 class PubspecEnvironment {
   /// The version constraint specifying which SDK versions this package works
   /// with.
   final VersionConstraint sdkVersion;
 
   PubspecEnvironment([VersionConstraint sdk])
       : sdkVersion = sdk != null ? sdk : VersionConstraint.any;
 }