Hook in the version solver to pub install.

utils/pub/entrypoint.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('entrypoint');
 
 #import('io.dart');
 #import('package.dart');
+#import('root_source.dart');
 #import('system_cache.dart');
 #import('version.dart');
+#import('version_solver.dart');
 #import('utils.dart');
 
 /**
  * Pub operates over a directed graph of dependencies that starts at a root
  * "entrypoint" package. This is typically the package where the current
  * working directory is located. An entrypoint knows the [root] package it is
  * associated with and is responsible for managing the "packages" directory
  * for it.
  *
  * That directory contains symlinks to all packages used by an app. These links
@@ skipping 84 matching lines @@
 
     return future;
   }
 
   /**
    * Installs all dependencies of the [root] package to its "packages"
    * directory. Returns a [Future] that completes when all dependencies are
    * installed.
    */
   Future installDependencies() {
-    var seen = new Set<PackageId>();
-
-    Future helper(List<PackageRef> packages) {
-      return Futures.wait(packages.map((ref) {
-        return resolve(ref).chain((id) {
-          if (seen.contains(id)) return new Future.immediate(null);
-          seen.add(id);
-
-          return install(id).chain((package) {
-            return helper(package.dependencies);
-          });
-        });
+    return resolveVersions(cache.sources, root).chain((packageVersions) {
+      // TODO(nweiz): persist packageVersions to a lockfile.
+      return Futures.wait(packageVersions.map((id) {
+        if (id.source is RootSource) return new Future.immediate(null);
+        return install(id);
       }));
-    }
-
-    return helper(root.dependencies);
-  }
-
-  /**
-   * Given [ref], which ambiguously identifies a dependent package, selects an
-   * appropriate precise package to use when this is the entrypoint. In other
-   * words, given a loose refence like "foo >= 2.0", figures out what concrete
-   * package we should use starting from this entrypoint.
-   */
-  Future<PackageId> resolve(PackageRef ref) {
-    // TODO(rnystrom): This should use the lockfile to select the right version
-    // once that's implemented. If the lockfile doesn't exist, it should
-    // generate it. In the meantime, here's a dumb implementation:
-    return new Future.immediate(ref.atVersion(ref.constraint));
+    });
   }
 }