diff --git a/src/applications/differential/query/DifferentialRevisionSearchEngine.php b/src/applications/differential/query/DifferentialRevisionSearchEngine.php
index 2199327678..87b25b9aad 100644
--- a/src/applications/differential/query/DifferentialRevisionSearchEngine.php
+++ b/src/applications/differential/query/DifferentialRevisionSearchEngine.php
@@ -1,329 +1,328 @@
 <?php
 
 final class DifferentialRevisionSearchEngine
   extends PhabricatorApplicationSearchEngine {
 
   public function getResultTypeDescription() {
     return pht('Differential Revisions');
   }
 
   public function getApplicationClassName() {
     return 'PhabricatorDifferentialApplication';
   }
 
   public function getPageSize(PhabricatorSavedQuery $saved) {
     if ($saved->getQueryKey() == 'active') {
       return 0xFFFF;
     }
     return parent::getPageSize($saved);
   }
 
   public function buildSavedQueryFromRequest(AphrontRequest $request) {
     $saved = new PhabricatorSavedQuery();
 
     $saved->setParameter(
       'responsiblePHIDs',
       $this->readUsersFromRequest($request, 'responsibles'));
 
     $saved->setParameter(
       'authorPHIDs',
       $this->readUsersFromRequest($request, 'authors'));
 
     $saved->setParameter(
       'reviewerPHIDs',
       $this->readUsersFromRequest(
         $request,
         'reviewers',
         array(
           PhabricatorProjectProjectPHIDType::TYPECONST,
         )));
 
     $saved->setParameter(
       'subscriberPHIDs',
-      $this->readUsersFromRequest($request, 'subscribers'));
+      $this->readSubscribersFromRequest($request, 'subscribers'));
 
     $saved->setParameter(
       'repositoryPHIDs',
       $request->getArr('repositories'));
 
-    // TODO: Implement "readProjectsFromRequest(...)" to improve this.
     $saved->setParameter(
       'projects',
-      $this->readListFromRequest($request, 'projects'));
+      $this->readProjectsFromRequest($request, 'projects'));
 
     $saved->setParameter(
       'draft',
       $request->getBool('draft'));
 
     $saved->setParameter(
       'order',
       $request->getStr('order'));
 
     $saved->setParameter(
       'status',
       $request->getStr('status'));
 
     return $saved;
   }
 
   public function buildQueryFromSavedQuery(PhabricatorSavedQuery $saved) {
     $query = id(new DifferentialRevisionQuery())
       ->needFlags(true)
       ->needDrafts(true)
       ->needRelationships(true);
 
     $datasource = id(new PhabricatorTypeaheadUserParameterizedDatasource())
       ->setViewer($this->requireViewer());
 
     $responsible_phids = $saved->getParameter('responsiblePHIDs', array());
     $responsible_phids = $datasource->evaluateTokens($responsible_phids);
     if ($responsible_phids) {
       $query->withResponsibleUsers($responsible_phids);
     }
 
     $this->setQueryProjects($query, $saved);
 
     $author_phids = $saved->getParameter('authorPHIDs', array());
     if ($author_phids) {
       $query->withAuthors($author_phids);
     }
 
     $reviewer_phids = $saved->getParameter('reviewerPHIDs', array());
     if ($reviewer_phids) {
       $query->withReviewers($reviewer_phids);
     }
 
     $subscriber_phids = $saved->getParameter('subscriberPHIDs', array());
     if ($subscriber_phids) {
       $query->withCCs($subscriber_phids);
     }
 
     $repository_phids = $saved->getParameter('repositoryPHIDs', array());
     if ($repository_phids) {
       $query->withRepositoryPHIDs($repository_phids);
     }
 
     $draft = $saved->getParameter('draft', false);
     if ($draft && $this->requireViewer()->isLoggedIn()) {
       $query->withDraftRepliesByAuthors(
         array($this->requireViewer()->getPHID()));
     }
 
     $status = $saved->getParameter('status');
     if (idx($this->getStatusOptions(), $status)) {
       $query->withStatus($status);
     }
 
     $order = $saved->getParameter('order');
     if (idx($this->getOrderOptions(), $order)) {
       $query->setOrder($order);
     } else {
       $query->setOrder(DifferentialRevisionQuery::ORDER_CREATED);
     }
 
     return $query;
   }
 
   public function buildSearchForm(
     AphrontFormView $form,
     PhabricatorSavedQuery $saved) {
 
     $responsible_phids = $saved->getParameter('responsiblePHIDs', array());
     $author_phids = $saved->getParameter('authorPHIDs', array());
     $reviewer_phids = $saved->getParameter('reviewerPHIDs', array());
     $subscriber_phids = $saved->getParameter('subscriberPHIDs', array());
     $repository_phids = $saved->getParameter('repositoryPHIDs', array());
     $only_draft = $saved->getParameter('draft', false);
     $projects = $saved->getParameter('projects', array());
 
     $form
       ->appendControl(
         id(new AphrontFormTokenizerControl())
           ->setLabel(pht('Responsible Users'))
           ->setName('responsibles')
           ->setDatasource(new PhabricatorTypeaheadUserParameterizedDatasource())
           ->setValue($responsible_phids))
       ->appendControl(
         id(new AphrontFormTokenizerControl())
           ->setLabel(pht('Authors'))
           ->setName('authors')
           ->setDatasource(new PhabricatorPeopleDatasource())
           ->setValue($author_phids))
       ->appendControl(
         id(new AphrontFormTokenizerControl())
           ->setLabel(pht('Reviewers'))
           ->setName('reviewers')
           ->setDatasource(new PhabricatorProjectOrUserDatasource())
           ->setValue($reviewer_phids))
       ->appendControl(
         id(new AphrontFormTokenizerControl())
           ->setLabel(pht('Subscribers'))
           ->setName('subscribers')
           ->setDatasource(new PhabricatorMetaMTAMailableDatasource())
           ->setValue($subscriber_phids))
       ->appendControl(
         id(new AphrontFormTokenizerControl())
           ->setLabel(pht('Repositories'))
           ->setName('repositories')
           ->setDatasource(new DiffusionRepositoryDatasource())
           ->setValue($repository_phids))
       ->appendControl(
         id(new AphrontFormTokenizerControl())
           ->setLabel(pht('Projects'))
           ->setName('projects')
           ->setDatasource(new PhabricatorProjectLogicalDatasource())
           ->setValue($projects))
       ->appendChild(
         id(new AphrontFormSelectControl())
           ->setLabel(pht('Status'))
           ->setName('status')
           ->setOptions($this->getStatusOptions())
           ->setValue($saved->getParameter('status')));
 
     if ($this->requireViewer()->isLoggedIn()) {
       $form
         ->appendChild(
           id(new AphrontFormCheckboxControl())
             ->addCheckbox(
               'draft',
               1,
               pht('Show only revisions with a draft comment.'),
               $only_draft));
     }
 
     $form
       ->appendChild(
         id(new AphrontFormSelectControl())
           ->setLabel(pht('Order'))
           ->setName('order')
           ->setOptions($this->getOrderOptions())
           ->setValue($saved->getParameter('order')));
   }
 
   protected function getURI($path) {
     return '/differential/'.$path;
   }
 
   protected function getBuiltinQueryNames() {
     $names = array();
 
     if ($this->requireViewer()->isLoggedIn()) {
       $names['active'] = pht('Active Revisions');
       $names['authored'] = pht('Authored');
     }
 
     $names['all'] = pht('All Revisions');
 
     return $names;
   }
 
   public function buildSavedQueryFromBuiltin($query_key) {
     $query = $this->newSavedQuery();
     $query->setQueryKey($query_key);
 
     $viewer = $this->requireViewer();
 
     switch ($query_key) {
       case 'active':
         return $query
           ->setParameter('responsiblePHIDs', array($viewer->getPHID()))
           ->setParameter('status', DifferentialRevisionQuery::STATUS_OPEN);
       case 'authored':
         return $query
           ->setParameter('authorPHIDs', array($viewer->getPHID()));
       case 'all':
         return $query;
     }
 
     return parent::buildSavedQueryFromBuiltin($query_key);
   }
 
   private function getStatusOptions() {
     return array(
       DifferentialRevisionQuery::STATUS_ANY            => pht('All'),
       DifferentialRevisionQuery::STATUS_OPEN           => pht('Open'),
       DifferentialRevisionQuery::STATUS_ACCEPTED       => pht('Accepted'),
       DifferentialRevisionQuery::STATUS_NEEDS_REVIEW   => pht('Needs Review'),
       DifferentialRevisionQuery::STATUS_NEEDS_REVISION => pht('Needs Revision'),
       DifferentialRevisionQuery::STATUS_CLOSED         => pht('Closed'),
       DifferentialRevisionQuery::STATUS_ABANDONED      => pht('Abandoned'),
     );
   }
 
   private function getOrderOptions() {
     return array(
       DifferentialRevisionQuery::ORDER_CREATED    => pht('Created'),
       DifferentialRevisionQuery::ORDER_MODIFIED   => pht('Updated'),
     );
   }
 
   protected function renderResultList(
     array $revisions,
     PhabricatorSavedQuery $query,
     array $handles) {
     assert_instances_of($revisions, 'DifferentialRevision');
 
     $viewer = $this->requireViewer();
     $template = id(new DifferentialRevisionListView())
       ->setUser($viewer)
       ->setNoBox($this->isPanelContext());
 
     $views = array();
     if ($query->getQueryKey() == 'active') {
         $split = DifferentialRevisionQuery::splitResponsible(
           $revisions,
           $query->getParameter('responsiblePHIDs'));
         list($blocking, $active, $waiting) = $split;
 
       $views[] = id(clone $template)
         ->setHeader(pht('Blocking Others'))
         ->setNoDataString(
           pht('No revisions are blocked on your action.'))
         ->setHighlightAge(true)
         ->setRevisions($blocking)
         ->setHandles(array());
 
       $views[] = id(clone $template)
         ->setHeader(pht('Action Required'))
         ->setNoDataString(
           pht('No revisions require your action.'))
         ->setHighlightAge(true)
         ->setRevisions($active)
         ->setHandles(array());
 
       $views[] = id(clone $template)
         ->setHeader(pht('Waiting on Others'))
         ->setNoDataString(
           pht('You have no revisions waiting on others.'))
         ->setRevisions($waiting)
         ->setHandles(array());
     } else {
       $views[] = id(clone $template)
         ->setRevisions($revisions)
         ->setHandles(array());
     }
 
     $phids = array_mergev(mpull($views, 'getRequiredHandlePHIDs'));
     if ($phids) {
       $handles = id(new PhabricatorHandleQuery())
         ->setViewer($viewer)
         ->withPHIDs($phids)
         ->execute();
     } else {
       $handles = array();
     }
 
     foreach ($views as $view) {
       $view->setHandles($handles);
     }
 
     if (count($views) == 1) {
       // Reduce this to a PHUIObjectItemListView so we can get the free
       // support from ApplicationSearch.
       return head($views)->render();
     } else {
       return $views;
     }
   }
 
 }
diff --git a/src/applications/phid/PhabricatorPHIDConstants.php b/src/applications/phid/PhabricatorPHIDConstants.php
index b92ecdf1c1..1688042fb1 100644
--- a/src/applications/phid/PhabricatorPHIDConstants.php
+++ b/src/applications/phid/PhabricatorPHIDConstants.php
@@ -1,19 +1,18 @@
 <?php
 
 final class PhabricatorPHIDConstants {
 
-  const PHID_TYPE_USER    = 'USER';
   const PHID_TYPE_UNKNOWN = '????';
   const PHID_TYPE_MAGIC   = '!!!!';
   const PHID_TYPE_STRY    = 'STRY';
   const PHID_TYPE_TOBJ    = 'TOBJ';
   const PHID_TYPE_LEGB    = 'LEGB';
 
   const PHID_TYPE_XCMT    = 'XCMT';
 
   const PHID_TYPE_XOBJ    = 'XOBJ';
 
   const PHID_TYPE_VOID    = 'VOID';
   const PHID_VOID         = 'PHID-VOID-00000000000000000000';
 
 }
diff --git a/src/applications/project/typeahead/PhabricatorProjectLogicalUserDatasource.php b/src/applications/project/typeahead/PhabricatorProjectLogicalUserDatasource.php
index 7a50d37f1e..ed1ebdc782 100644
--- a/src/applications/project/typeahead/PhabricatorProjectLogicalUserDatasource.php
+++ b/src/applications/project/typeahead/PhabricatorProjectLogicalUserDatasource.php
@@ -1,85 +1,123 @@
 <?php
 
 final class PhabricatorProjectLogicalUserDatasource
   extends PhabricatorTypeaheadCompositeDatasource {
 
   public function getPlaceholderText() {
     return pht('Type projects(<user>)...');
   }
 
   public function getDatasourceApplicationClass() {
     return 'PhabricatorProjectApplication';
   }
 
   public function getComponentDatasources() {
     return array(
       new PhabricatorPeopleDatasource(),
     );
   }
 
   public function getDatasourceFunctions() {
     return array(
       'projects' => array(
         'name' => pht("Find results in any of a user's projects."),
       ),
     );
   }
 
   protected function didLoadResults(array $results) {
     foreach ($results as $result) {
       $result
         ->setTokenType(PhabricatorTypeaheadTokenView::TYPE_FUNCTION)
         ->setIcon('fa-asterisk')
         ->setPHID('projects('.$result->getPHID().')')
         ->setDisplayName(pht("User's Projects: %s", $result->getDisplayName()))
         ->setName($result->getName().' projects');
     }
 
     return $results;
   }
 
   protected function evaluateFunction($function, array $argv_list) {
     $phids = array();
     foreach ($argv_list as $argv) {
       $phids[] = head($argv);
     }
 
+    $phids = $this->resolvePHIDs($phids);
+
     $projects = id(new PhabricatorProjectQuery())
       ->setViewer($this->getViewer())
       ->withMemberPHIDs($phids)
       ->execute();
 
     $results = array();
     foreach ($projects as $project) {
       $results[] = new PhabricatorQueryConstraint(
         PhabricatorQueryConstraint::OPERATOR_OR,
         $project->getPHID());
     }
 
     return $results;
   }
 
   public function renderFunctionTokens($function, array $argv_list) {
     $phids = array();
     foreach ($argv_list as $argv) {
       $phids[] = head($argv);
     }
 
+    $phids = $this->resolvePHIDs($phids);
+
     $tokens = $this->renderTokens($phids);
     foreach ($tokens as $token) {
       if ($token->isInvalid()) {
         $token
           ->setValue(pht("User's Projects: Invalid User"));
       } else {
         $token
           ->setIcon('fa-asterisk')
           ->setTokenType(PhabricatorTypeaheadTokenView::TYPE_FUNCTION)
           ->setKey('projects('.$token->getKey().')')
           ->setValue(pht("User's Projects: %s", $token->getValue()));
       }
     }
 
     return $tokens;
   }
 
+  private function resolvePHIDs(array $phids) {
+    // If we have a function like `projects(alincoln)`, try to resolve the
+    // username first. This won't happen normally, but can be passed in from
+    // the query string.
+
+    // The user might also give us an invalid username. In this case, we
+    // preserve it and return it in-place so we get an "invalid" token rendered
+    // in the UI. This shows the user where the issue is and  best represents
+    // the user's input.
+
+    $usernames = array();
+    foreach ($phids as $key => $phid) {
+      if (phid_get_type($phid) != PhabricatorPeopleUserPHIDType::TYPECONST) {
+        $usernames[$key] = $phid;
+      }
+    }
+
+    if ($usernames) {
+      $users = id(new PhabricatorPeopleQuery())
+        ->setViewer($this->getViewer())
+        ->withUsernames($usernames)
+        ->execute();
+      $users = mpull($users, null, 'getUsername');
+      foreach ($usernames as $key => $username) {
+        $user = idx($users, $username);
+        if ($user) {
+          $phids[$key] = $user->getPHID();
+        }
+      }
+    }
+
+    return $phids;
+  }
+
 }
diff --git a/src/applications/search/engine/PhabricatorApplicationSearchEngine.php b/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
index 13ee728fc2..d260f03aeb 100644
--- a/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
+++ b/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
@@ -1,965 +1,1029 @@
 <?php
 
 /**
  * Represents an abstract search engine for an application. It supports
  * creating and storing saved queries.
  *
  * @task construct  Constructing Engines
  * @task app        Applications
  * @task builtin    Builtin Queries
  * @task uri        Query URIs
  * @task dates      Date Filters
  * @task order      Result Ordering
  * @task read       Reading Utilities
  * @task exec       Paging and Executing Queries
  * @task render     Rendering Results
  */
 abstract class PhabricatorApplicationSearchEngine {
 
   private $application;
   private $viewer;
   private $errors = array();
   private $customFields = false;
   private $request;
   private $context;
 
   const CONTEXT_LIST  = 'list';
   const CONTEXT_PANEL = 'panel';
 
   public function setViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
     return $this;
   }
 
   protected function requireViewer() {
     if (!$this->viewer) {
       throw new Exception('Call setViewer() before using an engine!');
     }
     return $this->viewer;
   }
 
   public function setContext($context) {
     $this->context = $context;
     return $this;
   }
 
   public function isPanelContext() {
     return ($this->context == self::CONTEXT_PANEL);
   }
 
   public function canUseInPanelContext() {
     return true;
   }
 
   public function saveQuery(PhabricatorSavedQuery $query) {
     $query->setEngineClassName(get_class($this));
 
     $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
     try {
       $query->save();
     } catch (AphrontDuplicateKeyQueryException $ex) {
       // Ignore, this is just a repeated search.
     }
     unset($unguarded);
   }
 
   /**
    * Create a saved query object from the request.
    *
    * @param AphrontRequest The search request.
    * @return PhabricatorSavedQuery
    */
   abstract public function buildSavedQueryFromRequest(
     AphrontRequest $request);
 
   /**
    * Executes the saved query.
    *
    * @param PhabricatorSavedQuery The saved query to operate on.
    * @return The result of the query.
    */
   abstract public function buildQueryFromSavedQuery(
     PhabricatorSavedQuery $saved);
 
   /**
    * Builds the search form using the request.
    *
    * @param AphrontFormView       Form to populate.
    * @param PhabricatorSavedQuery The query from which to build the form.
    * @return void
    */
   abstract public function buildSearchForm(
     AphrontFormView $form,
     PhabricatorSavedQuery $query);
 
   public function getErrors() {
     return $this->errors;
   }
 
   public function addError($error) {
     $this->errors[] = $error;
     return $this;
   }
 
   /**
    * Return an application URI corresponding to the results page of a query.
    * Normally, this is something like `/application/query/QUERYKEY/`.
    *
    * @param   string  The query key to build a URI for.
    * @return  string  URI where the query can be executed.
    * @task uri
    */
   public function getQueryResultsPageURI($query_key) {
     return $this->getURI('query/'.$query_key.'/');
   }
 
 
   /**
    * Return an application URI for query management. This is used when, e.g.,
    * a query deletion operation is cancelled.
    *
    * @return  string  URI where queries can be managed.
    * @task uri
    */
   public function getQueryManagementURI() {
     return $this->getURI('query/edit/');
   }
 
 
   /**
    * Return the URI to a path within the application. Used to construct default
    * URIs for management and results.
    *
    * @return string URI to path.
    * @task uri
    */
   abstract protected function getURI($path);
 
 
   /**
    * Return a human readable description of the type of objects this query
    * searches for.
    *
    * For example, "Tasks" or "Commits".
    *
    * @return string Human-readable description of what this engine is used to
    *   find.
    */
   abstract public function getResultTypeDescription();
 
 
   public function newSavedQuery() {
     return id(new PhabricatorSavedQuery())
       ->setEngineClassName(get_class($this));
   }
 
   public function addNavigationItems(PHUIListView $menu) {
     $viewer = $this->requireViewer();
 
     $menu->newLabel(pht('Queries'));
 
     $named_queries = $this->loadEnabledNamedQueries();
 
     foreach ($named_queries as $query) {
       $key = $query->getQueryKey();
       $uri = $this->getQueryResultsPageURI($key);
       $menu->newLink($query->getQueryName(), $uri, 'query/'.$key);
     }
 
     if ($viewer->isLoggedIn()) {
       $manage_uri = $this->getQueryManagementURI();
       $menu->newLink(pht('Edit Queries...'), $manage_uri, 'query/edit');
     }
 
     $menu->newLabel(pht('Search'));
     $advanced_uri = $this->getQueryResultsPageURI('advanced');
     $menu->newLink(pht('Advanced Search'), $advanced_uri, 'query/advanced');
 
     return $this;
   }
 
   public function loadAllNamedQueries() {
     $viewer = $this->requireViewer();
 
     $named_queries = id(new PhabricatorNamedQueryQuery())
       ->setViewer($viewer)
       ->withUserPHIDs(array($viewer->getPHID()))
       ->withEngineClassNames(array(get_class($this)))
       ->execute();
     $named_queries = mpull($named_queries, null, 'getQueryKey');
 
     $builtin = $this->getBuiltinQueries($viewer);
     $builtin = mpull($builtin, null, 'getQueryKey');
 
     foreach ($named_queries as $key => $named_query) {
       if ($named_query->getIsBuiltin()) {
         if (isset($builtin[$key])) {
           $named_queries[$key]->setQueryName($builtin[$key]->getQueryName());
           unset($builtin[$key]);
         } else {
           unset($named_queries[$key]);
         }
       }
 
       unset($builtin[$key]);
     }
 
     $named_queries = msort($named_queries, 'getSortKey');
 
     return $named_queries + $builtin;
   }
 
   public function loadEnabledNamedQueries() {
     $named_queries = $this->loadAllNamedQueries();
     foreach ($named_queries as $key => $named_query) {
       if ($named_query->getIsBuiltin() && $named_query->getIsDisabled()) {
         unset($named_queries[$key]);
       }
     }
     return $named_queries;
   }
 
   protected function setQueryProjects(
     PhabricatorCursorPagedPolicyAwareQuery $query,
     PhabricatorSavedQuery $saved) {
 
     $datasource = id(new PhabricatorProjectLogicalDatasource())
       ->setViewer($this->requireViewer());
 
     $projects = $saved->getParameter('projects', array());
     $constraints = $datasource->evaluateTokens($projects);
 
     if ($constraints) {
       $query->withEdgeLogicConstraints(
         PhabricatorProjectObjectHasProjectEdgeType::EDGECONST,
         $constraints);
     }
   }
 
 
 /* -(  Applications  )------------------------------------------------------- */
 
 
   protected function getApplicationURI($path = '') {
     return $this->getApplication()->getApplicationURI($path);
   }
 
   protected function getApplication() {
     if (!$this->application) {
       $class = $this->getApplicationClassName();
 
       $this->application = id(new PhabricatorApplicationQuery())
         ->setViewer($this->requireViewer())
         ->withClasses(array($class))
         ->withInstalled(true)
         ->executeOne();
 
       if (!$this->application) {
         throw new Exception(
           pht(
             'Application "%s" is not installed!',
             $class));
       }
     }
 
     return $this->application;
   }
 
   abstract public function getApplicationClassName();
 
 
 /* -(  Constructing Engines  )----------------------------------------------- */
 
 
   /**
    * Load all available application search engines.
    *
    * @return list<PhabricatorApplicationSearchEngine> All available engines.
    * @task construct
    */
   public static function getAllEngines() {
     $engines = id(new PhutilSymbolLoader())
       ->setAncestorClass(__CLASS__)
       ->loadObjects();
 
     return $engines;
   }
 
 
   /**
    * Get an engine by class name, if it exists.
    *
    * @return PhabricatorApplicationSearchEngine|null Engine, or null if it does
    *   not exist.
    * @task construct
    */
   public static function getEngineByClassName($class_name) {
     return idx(self::getAllEngines(), $class_name);
   }
 
 
 /* -(  Builtin Queries  )---------------------------------------------------- */
 
 
   /**
    * @task builtin
    */
   public function getBuiltinQueries() {
     $names = $this->getBuiltinQueryNames();
 
     $queries = array();
     $sequence = 0;
     foreach ($names as $key => $name) {
       $queries[$key] = id(new PhabricatorNamedQuery())
         ->setUserPHID($this->requireViewer()->getPHID())
         ->setEngineClassName(get_class($this))
         ->setQueryName($name)
         ->setQueryKey($key)
         ->setSequence((1 << 24) + $sequence++)
         ->setIsBuiltin(true);
     }
 
     return $queries;
   }
 
 
   /**
    * @task builtin
    */
   public function getBuiltinQuery($query_key) {
     if (!$this->isBuiltinQuery($query_key)) {
       throw new Exception("'{$query_key}' is not a builtin!");
     }
     return idx($this->getBuiltinQueries(), $query_key);
   }
 
 
   /**
    * @task builtin
    */
   protected function getBuiltinQueryNames() {
     return array();
   }
 
 
   /**
    * @task builtin
    */
   public function isBuiltinQuery($query_key) {
     $builtins = $this->getBuiltinQueries();
     return isset($builtins[$query_key]);
   }
 
 
   /**
    * @task builtin
    */
   public function buildSavedQueryFromBuiltin($query_key) {
     throw new Exception("Builtin '{$query_key}' is not supported!");
   }
 
 
 /* -(  Reading Utilities )--------------------------------------------------- */
 
 
   /**
    * Read a list of user PHIDs from a request in a flexible way. This method
    * supports either of these forms:
    *
    *   users[]=alincoln&users[]=htaft
    *   users=alincoln,htaft
    *
    * Additionally, users can be specified either by PHID or by name.
    *
    * The main goal of this flexibility is to allow external programs to generate
    * links to pages (like "alincoln's open revisions") without needing to make
    * API calls.
    *
    * @param AphrontRequest  Request to read user PHIDs from.
    * @param string          Key to read in the request.
    * @param list<const>     Other permitted PHID types.
-   * @return list<phid>     List of user PHIDs.
-   *
+   * @return list<phid>     List of user PHIDs and selector functions.
    * @task read
    */
   protected function readUsersFromRequest(
     AphrontRequest $request,
     $key,
     array $allow_types = array()) {
 
     $list = $this->readListFromRequest($request, $key);
 
     $phids = array();
     $names = array();
     $allow_types = array_fuse($allow_types);
-    $user_type = PhabricatorPHIDConstants::PHID_TYPE_USER;
+    $user_type = PhabricatorPeopleUserPHIDType::TYPECONST;
     foreach ($list as $item) {
       $type = phid_get_type($item);
       if ($type == $user_type) {
         $phids[] = $item;
       } else if (isset($allow_types[$type])) {
         $phids[] = $item;
       } else {
         if (PhabricatorTypeaheadDatasource::isFunctionToken($item)) {
           // If this is a function, pass it through unchanged; we'll evaluate
           // it later.
           $phids[] = $item;
         } else {
           $names[] = $item;
         }
       }
     }
 
     if ($names) {
       $users = id(new PhabricatorPeopleQuery())
         ->setViewer($this->requireViewer())
         ->withUsernames($names)
         ->execute();
       foreach ($users as $user) {
         $phids[] = $user->getPHID();
       }
       $phids = array_unique($phids);
     }
 
     return $phids;
   }
 
 
+  /**
+   * Read a list of project PHIDs from a request in a flexible way.
+   *
+   * @param AphrontRequest  Request to read user PHIDs from.
+   * @param string          Key to read in the request.
+   * @return list<phid>     List of projet PHIDs and selector functions.
+   * @task read
+   */
+  protected function readProjectsFromRequest(AphrontRequest $request, $key) {
+    $list = $this->readListFromRequest($request, $key);
+
+    $phids = array();
+    $slugs = array();
+    $project_type = PhabricatorProjectProjectPHIDType::TYPECONST;
+    foreach ($list as $item) {
+      $type = phid_get_type($item);
+      if ($type == $project_type) {
+        $phids[] = $item;
+      } else {
+        if (PhabricatorTypeaheadDatasource::isFunctionToken($item)) {
+          // If this is a function, pass it through unchanged; we'll evaluate
+          // it later.
+          $phids[] = $item;
+        } else {
+          $slugs[] = $item;
+        }
+      }
+    }
+
+    if ($slugs) {
+      $projects = id(new PhabricatorProjectQuery())
+        ->setViewer($this->requireViewer())
+        ->withSlugs($slugs)
+        ->execute();
+      foreach ($projects as $project) {
+        $phids[] = $project->getPHID();
+      }
+      $phids = array_unique($phids);
+    }
+
+    return $phids;
+  }
+
+
+  /**
+   * Read a list of subscribers from a request in a flexible way.
+   *
+   * @param AphrontRequest  Request to read PHIDs from.
+   * @param string          Key to read in the request.
+   * @return list<phid>     List of object PHIDs.
+   * @task read
+   */
+  protected function readSubscribersFromRequest(
+    AphrontRequest $request,
+    $key) {
+    return $this->readUsersFromRequest(
+      $request,
+      $key,
+      array(
+        PhabricatorProjectProjectPHIDType::TYPECONST,
+        PhabricatorMailingListListPHIDType::TYPECONST,
+      ));
+  }
+
+
   /**
    * Read a list of generic PHIDs from a request in a flexible way. Like
    * @{method:readUsersFromRequest}, this method supports either array or
    * comma-delimited forms. Objects can be specified either by PHID or by
    * object name.
    *
    * @param AphrontRequest  Request to read PHIDs from.
    * @param string          Key to read in the request.
    * @param list<const>     Optional, list of permitted PHID types.
    * @return list<phid>     List of object PHIDs.
    *
    * @task read
    */
   protected function readPHIDsFromRequest(
     AphrontRequest $request,
     $key,
     array $allow_types = array()) {
 
     $list = $this->readListFromRequest($request, $key);
 
     $objects = id(new PhabricatorObjectQuery())
       ->setViewer($this->requireViewer())
       ->withNames($list)
       ->execute();
     $list = mpull($objects, 'getPHID');
 
     if (!$list) {
       return array();
     }
 
     // If only certain PHID types are allowed, filter out all the others.
     if ($allow_types) {
       $allow_types = array_fuse($allow_types);
       foreach ($list as $key => $phid) {
         if (empty($allow_types[phid_get_type($phid)])) {
           unset($list[$key]);
         }
       }
     }
 
     return $list;
   }
 
 
   /**
    * Read a list of items from the request, in either array format or string
    * format:
    *
    *   list[]=item1&list[]=item2
    *   list=item1,item2
    *
    * This provides flexibility when constructing URIs, especially from external
    * sources.
    *
    * @param AphrontRequest  Request to read strings from.
    * @param string          Key to read in the request.
    * @return list<string>   List of values.
    */
   protected function readListFromRequest(
     AphrontRequest $request,
     $key) {
     $list = $request->getArr($key, null);
     if ($list === null) {
       $list = $request->getStrList($key);
     }
 
     if (!$list) {
       return array();
     }
 
     return $list;
   }
 
   protected function readDateFromRequest(
     AphrontRequest $request,
     $key) {
 
     return id(new AphrontFormDateControl())
       ->setUser($this->requireViewer())
       ->setName($key)
       ->setAllowNull(true)
       ->readValueFromRequest($request);
   }
 
   protected function readBoolFromRequest(
     AphrontRequest $request,
     $key) {
     if (!strlen($request->getStr($key))) {
       return null;
     }
     return $request->getBool($key);
   }
 
 
   protected function getBoolFromQuery(PhabricatorSavedQuery $query, $key) {
     $value = $query->getParameter($key);
     if ($value === null) {
       return $value;
     }
     return $value ? 'true' : 'false';
   }
 
 
 /* -(  Dates  )-------------------------------------------------------------- */
 
 
   /**
    * @task dates
    */
   protected function parseDateTime($date_time) {
     if (!strlen($date_time)) {
       return null;
     }
 
     return PhabricatorTime::parseLocalTime($date_time, $this->requireViewer());
   }
 
 
   /**
    * @task dates
    */
   protected function buildDateRange(
     AphrontFormView $form,
     PhabricatorSavedQuery $saved_query,
     $start_key,
     $start_name,
     $end_key,
     $end_name) {
 
     $start_str = $saved_query->getParameter($start_key);
     $start = null;
     if (strlen($start_str)) {
       $start = $this->parseDateTime($start_str);
       if (!$start) {
         $this->addError(
           pht(
             '"%s" date can not be parsed.',
             $start_name));
       }
     }
 
 
     $end_str = $saved_query->getParameter($end_key);
     $end = null;
     if (strlen($end_str)) {
       $end = $this->parseDateTime($end_str);
       if (!$end) {
         $this->addError(
           pht(
             '"%s" date can not be parsed.',
             $end_name));
       }
     }
 
     if ($start && $end && ($start >= $end)) {
       $this->addError(
         pht(
           '"%s" must be a date before "%s".',
           $start_name,
           $end_name));
     }
 
     $form
       ->appendChild(
         id(new PHUIFormFreeformDateControl())
           ->setName($start_key)
           ->setLabel($start_name)
           ->setValue($start_str))
       ->appendChild(
         id(new AphrontFormTextControl())
           ->setName($end_key)
           ->setLabel($end_name)
           ->setValue($end_str));
   }
 
 
 /* -(  Result Ordering  )---------------------------------------------------- */
 
 
   /**
    * Save order selection to a @{class:PhabricatorSavedQuery}.
    */
   protected function saveQueryOrder(
     PhabricatorSavedQuery $saved,
     AphrontRequest $request) {
 
     $saved->setParameter('order', $request->getStr('order'));
 
     return $this;
   }
 
 
   /**
    * Set query ordering from a saved value.
    */
   protected function setQueryOrder(
     PhabricatorCursorPagedPolicyAwareQuery $query,
     PhabricatorSavedQuery $saved) {
 
     $order = $saved->getParameter('order');
     $builtin = $query->getBuiltinOrders();
     if (strlen($order) && isset($builtin[$order])) {
       $query->setOrder($order);
     } else {
       // If the order is invalid or not available, we choose the first
       // builtin order. This isn't always the default order for the query,
       // but is the first value in the "Order" dropdown, and makes the query
       // behavior more consistent with the UI. In queries where the two
       // orders differ, this order is the preferred order for humans.
       $query->setOrder(head_key($builtin));
     }
 
     return $this;
   }
 
 
 
   protected function appendOrderFieldsToForm(
     AphrontFormView $form,
     PhabricatorSavedQuery $saved,
     PhabricatorCursorPagedPolicyAwareQuery $query) {
 
     $orders = $query->getBuiltinOrders();
     $orders = ipull($orders, 'name');
 
     $form->appendControl(
       id(new AphrontFormSelectControl())
         ->setLabel(pht('Order'))
         ->setName('order')
         ->setOptions($orders)
         ->setValue($saved->getParameter('order')));
   }
 
 /* -(  Paging and Executing Queries  )--------------------------------------- */
 
 
   public function getPageSize(PhabricatorSavedQuery $saved) {
     return $saved->getParameter('limit', 100);
   }
 
 
   public function shouldUseOffsetPaging() {
     return false;
   }
 
 
   public function newPagerForSavedQuery(PhabricatorSavedQuery $saved) {
     if ($this->shouldUseOffsetPaging()) {
       $pager = new AphrontPagerView();
     } else {
       $pager = new AphrontCursorPagerView();
     }
 
     $page_size = $this->getPageSize($saved);
     if (is_finite($page_size)) {
       $pager->setPageSize($page_size);
     } else {
       // Consider an INF pagesize to mean a large finite pagesize.
 
       // TODO: It would be nice to handle this more gracefully, but math
       // with INF seems to vary across PHP versions, systems, and runtimes.
       $pager->setPageSize(0xFFFF);
     }
 
     return $pager;
   }
 
 
   public function executeQuery(
     PhabricatorPolicyAwareQuery $query,
     AphrontView $pager) {
 
     $query->setViewer($this->requireViewer());
 
     if ($this->shouldUseOffsetPaging()) {
       $objects = $query->executeWithOffsetPager($pager);
     } else {
       $objects = $query->executeWithCursorPager($pager);
     }
 
     return $objects;
   }
 
 
 /* -(  Rendering  )---------------------------------------------------------- */
 
 
   public function setRequest(AphrontRequest $request) {
     $this->request = $request;
     return $this;
   }
 
   public function getRequest() {
     return $this->request;
   }
 
   public function renderResults(
     array $objects,
     PhabricatorSavedQuery $query) {
 
     $phids = $this->getRequiredHandlePHIDsForResultList($objects, $query);
 
     if ($phids) {
       $handles = id(new PhabricatorHandleQuery())
         ->setViewer($this->requireViewer())
         ->witHPHIDs($phids)
         ->execute();
     } else {
       $handles = array();
     }
 
     return $this->renderResultList($objects, $query, $handles);
   }
 
   protected function getRequiredHandlePHIDsForResultList(
     array $objects,
     PhabricatorSavedQuery $query) {
     return array();
   }
 
   protected function renderResultList(
     array $objects,
     PhabricatorSavedQuery $query,
     array $handles) {
     throw new Exception(pht('Not supported here yet!'));
   }
 
 
 /* -(  Application Search  )------------------------------------------------- */
 
 
   /**
    * Retrieve an object to use to define custom fields for this search.
    *
    * To integrate with custom fields, subclasses should override this method
    * and return an instance of the application object which implements
    * @{interface:PhabricatorCustomFieldInterface}.
    *
    * @return PhabricatorCustomFieldInterface|null Object with custom fields.
    * @task appsearch
    */
   public function getCustomFieldObject() {
     return null;
   }
 
 
   /**
    * Get the custom fields for this search.
    *
    * @return PhabricatorCustomFieldList|null Custom fields, if this search
    *   supports custom fields.
    * @task appsearch
    */
   public function getCustomFieldList() {
     if ($this->customFields === false) {
       $object = $this->getCustomFieldObject();
       if ($object) {
         $fields = PhabricatorCustomField::getObjectFields(
           $object,
           PhabricatorCustomField::ROLE_APPLICATIONSEARCH);
         $fields->setViewer($this->requireViewer());
       } else {
         $fields = null;
       }
       $this->customFields = $fields;
     }
     return $this->customFields;
   }
 
 
   /**
    * Moves data from the request into a saved query.
    *
    * @param AphrontRequest Request to read.
    * @param PhabricatorSavedQuery Query to write to.
    * @return void
    * @task appsearch
    */
   protected function readCustomFieldsFromRequest(
     AphrontRequest $request,
     PhabricatorSavedQuery $saved) {
 
     $list = $this->getCustomFieldList();
     if (!$list) {
       return;
     }
 
     foreach ($list->getFields() as $field) {
       $key = $this->getKeyForCustomField($field);
       $value = $field->readApplicationSearchValueFromRequest(
         $this,
         $request);
       $saved->setParameter($key, $value);
     }
   }
 
 
   /**
    * Applies data from a saved query to an executable query.
    *
    * @param PhabricatorCursorPagedPolicyAwareQuery Query to constrain.
    * @param PhabricatorSavedQuery Saved query to read.
    * @return void
    */
   protected function applyCustomFieldsToQuery(
     PhabricatorCursorPagedPolicyAwareQuery $query,
     PhabricatorSavedQuery $saved) {
 
     $list = $this->getCustomFieldList();
     if (!$list) {
       return;
     }
 
     foreach ($list->getFields() as $field) {
       $key = $this->getKeyForCustomField($field);
       $value = $field->applyApplicationSearchConstraintToQuery(
         $this,
         $query,
         $saved->getParameter($key));
     }
   }
 
   protected function applyOrderByToQuery(
     PhabricatorCursorPagedPolicyAwareQuery $query,
     array $standard_values,
     $order) {
 
     if (substr($order, 0, 7) === 'custom:') {
       $list = $this->getCustomFieldList();
       if (!$list) {
         $query->setOrderBy(head($standard_values));
         return;
       }
 
       foreach ($list->getFields() as $field) {
         $key = $this->getKeyForCustomField($field);
 
         if ($key === $order) {
           $index = $field->buildOrderIndex();
 
           if ($index === null) {
             $query->setOrderBy(head($standard_values));
             return;
           }
 
           $query->withApplicationSearchOrder(
             $field,
             $index,
             false);
           break;
         }
       }
     } else {
       $order = idx($standard_values, $order);
       if ($order) {
         $query->setOrderBy($order);
       } else {
         $query->setOrderBy(head($standard_values));
       }
     }
   }
 
 
   protected function getCustomFieldOrderOptions() {
     $list = $this->getCustomFieldList();
     if (!$list) {
       return;
     }
 
     $custom_order = array();
     foreach ($list->getFields() as $field) {
       if ($field->shouldAppearInApplicationSearch()) {
         if ($field->buildOrderIndex() !== null) {
           $key = $this->getKeyForCustomField($field);
           $custom_order[$key] = $field->getFieldName();
         }
       }
     }
 
     return $custom_order;
   }
 
   /**
    * Get a unique key identifying a field.
    *
    * @param PhabricatorCustomField Field to identify.
    * @return string Unique identifier, suitable for use as an input name.
    */
   public function getKeyForCustomField(PhabricatorCustomField $field) {
     return 'custom:'.$field->getFieldIndex();
   }
 
 
   /**
    * Add inputs to an application search form so the user can query on custom
    * fields.
    *
    * @param AphrontFormView Form to update.
    * @param PhabricatorSavedQuery Values to prefill.
    * @return void
    */
   protected function appendCustomFieldsToForm(
     AphrontFormView $form,
     PhabricatorSavedQuery $saved) {
 
     $list = $this->getCustomFieldList();
     if (!$list) {
       return;
     }
 
     $phids = array();
     foreach ($list->getFields() as $field) {
       $key = $this->getKeyForCustomField($field);
       $value = $saved->getParameter($key);
       $phids[$key] = $field->getRequiredHandlePHIDsForApplicationSearch($value);
     }
     $all_phids = array_mergev($phids);
 
     $handles = array();
     if ($all_phids) {
       $handles = id(new PhabricatorHandleQuery())
         ->setViewer($this->requireViewer())
         ->withPHIDs($all_phids)
         ->execute();
     }
 
     foreach ($list->getFields() as $field) {
       $key = $this->getKeyForCustomField($field);
       $value = $saved->getParameter($key);
       $field->appendToApplicationSearchForm(
         $this,
         $form,
         $value,
         array_select_keys($handles, $phids[$key]));
     }
   }
 
 }