{"action":"created","comment":{"url":"https://api.github.com/repos/akka/akka/pulls/comments/45193316","id":45193316,"diff_hunk":"@@ -142,6 +142,62 @@ private[akka] final class HeadOptionSink[In](val attributes: Attributes, shape:\n \n /**\n  * INTERNAL API\n+ */\n+private[akka] object LastSink {\n+  final class LastOptionSinkSubscriber[In] extends Subscriber[In] {\n+    private[this] var prev: In = null.asInstanceOf[In]\n+    private[this] var subscription: Subscription = null\n+    private[this] val promise: Promise[Option[In]] = Promise[Option[In]]()\n+    def future: Future[Option[In]] = promise.future\n+    override def onSubscribe(s: Subscription): Unit = {\n+      ReactiveStreamsCompliance.requireNonNullSubscription(s)\n+      if (subscription ne null) s.cancel()\n+      else {\n+        subscription = s\n+        s.request(Long.MaxValue)\n+      }\n+    }\n+\n+    override def onNext(elem: In): Unit = {\n+      ReactiveStreamsCompliance.requireNonNullElement(elem)\n+      prev = elem\n+    }\n+\n+    override def onError(t: Throwable): Unit = {\n+      ReactiveStreamsCompliance.requireNonNullException(t)\n+      promise.tryFailure(t)\n+      subscription = null\n+    }\n+\n+    override def onComplete(): Unit = {\n+      promise.trySuccess(Option(prev))\n+      prev = null.asInstanceOf[In]\n+      subscription = null\n+    }\n+  }","path":"akka-stream/src/main/scala/akka/stream/impl/Sinks.scala","position":36,"original_position":36,"commit_id":"369c1dd643666d29a25cd119b957c5087d58ff95","original_commit_id":"369c1dd643666d29a25cd119b957c5087d58ff95","user":{"login":"ktoso","id":120979,"avatar_url":"https://avatars.githubusercontent.com/u/120979?v=3","gravatar_id":"","url":"https://api.github.com/users/ktoso","html_url":"https://github.com/ktoso","followers_url":"https://api.github.com/users/ktoso/followers","following_url":"https://api.github.com/users/ktoso/following{/other_user}","gists_url":"https://api.github.com/users/ktoso/gists{/gist_id}","starred_url":"https://api.github.com/users/ktoso/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ktoso/subscriptions","organizations_url":"https://api.github.com/users/ktoso/orgs","repos_url":"https://api.github.com/users/ktoso/repos","events_url":"https://api.github.com/users/ktoso/events{/privacy}","received_events_url":"https://api.github.com/users/ktoso/received_events","type":"User","site_admin":false},"body":"raw Subscriber implementation would be good to TCK test (we do still bump into silly mistakes with them ince in a while) though not sure how many tests such one would pass (semantics wise), have you had a look?","created_at":"2015-11-18T12:33:40Z","updated_at":"2015-11-18T12:33:40Z","html_url":"https://github.com/akka/akka/pull/18951#discussion_r45193316","pull_request_url":"https://api.github.com/repos/akka/akka/pulls/18951","_links":{"self":{"href":"https://api.github.com/repos/akka/akka/pulls/comments/45193316"},"html":{"href":"https://github.com/akka/akka/pull/18951#discussion_r45193316"},"pull_request":{"href":"https://api.github.com/repos/akka/akka/pulls/18951"}}},"pull_request":{"url":"https://api.github.com/repos/akka/akka/pulls/18951","id":51019279,"html_url":"https://github.com/akka/akka/pull/18951","diff_url":"https://github.com/akka/akka/pull/18951.diff","patch_url":"https://github.com/akka/akka/pull/18951.patch","issue_url":"https://api.github.com/repos/akka/akka/issues/18951","number":18951,"state":"open","locked":false,"title":"+str - Adds Sink.last and Sink.lastOption to mirror Sink.head and Sin…","user":{"login":"viktorklang","id":10871,"avatar_url":"https://avatars.githubusercontent.com/u/10871?v=3","gravatar_id":"","url":"https://api.github.com/users/viktorklang","html_url":"https://github.com/viktorklang","followers_url":"https://api.github.com/users/viktorklang/followers","following_url":"https://api.github.com/users/viktorklang/following{/other_user}","gists_url":"https://api.github.com/users/viktorklang/gists{/gist_id}","starred_url":"https://api.github.com/users/viktorklang/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/viktorklang/subscriptions","organizations_url":"https://api.github.com/users/viktorklang/orgs","repos_url":"https://api.github.com/users/viktorklang/repos","events_url":"https://api.github.com/users/viktorklang/events{/privacy}","received_events_url":"https://api.github.com/users/viktorklang/received_events","type":"User","site_admin":false},"body":"…k.headOption\r\n\r\n\r\nThoughts?","created_at":"2015-11-17T23:09:58Z","updated_at":"2015-11-18T12:33:40Z","closed_at":null,"merged_at":null,"merge_commit_sha":"2035515a683ff0ac9e3b26374970eddff6cabed1","assignee":null,"milestone":null,"commits_url":"https://api.github.com/repos/akka/akka/pulls/18951/commits","review_comments_url":"https://api.github.com/repos/akka/akka/pulls/18951/comments","review_comment_url":"https://api.github.com/repos/akka/akka/pulls/comments{/number}","comments_url":"https://api.github.com/repos/akka/akka/issues/18951/comments","statuses_url":"https://api.github.com/repos/akka/akka/statuses/369c1dd643666d29a25cd119b957c5087d58ff95","head":{"label":"akka:wip-add-sink-last-√","ref":"wip-add-sink-last-√","sha":"369c1dd643666d29a25cd119b957c5087d58ff95","user":{"login":"akka","id":1496237,"avatar_url":"https://avatars.githubusercontent.com/u/1496237?v=3","gravatar_id":"","url":"https://api.github.com/users/akka","html_url":"https://github.com/akka","followers_url":"https://api.github.com/users/akka/followers","following_url":"https://api.github.com/users/akka/following{/other_user}","gists_url":"https://api.github.com/users/akka/gists{/gist_id}","starred_url":"https://api.github.com/users/akka/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/akka/subscriptions","organizations_url":"https://api.github.com/users/akka/orgs","repos_url":"https://api.github.com/users/akka/repos","events_url":"https://api.github.com/users/akka/events{/privacy}","received_events_url":"https://api.github.com/users/akka/received_events","type":"Organization","site_admin":false},"repo":{"id":130013,"name":"akka","full_name":"akka/akka","owner":{"login":"akka","id":1496237,"avatar_url":"https://avatars.githubusercontent.com/u/1496237?v=3","gravatar_id":"","url":"https://api.github.com/users/akka","html_url":"https://github.com/akka","followers_url":"https://api.github.com/users/akka/followers","following_url":"https://api.github.com/users/akka/following{/other_user}","gists_url":"https://api.github.com/users/akka/gists{/gist_id}","starred_url":"https://api.github.com/users/akka/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/akka/subscriptions","organizations_url":"https://api.github.com/users/akka/orgs","repos_url":"https://api.github.com/users/akka/repos","events_url":"https://api.github.com/users/akka/events{/privacy}","received_events_url":"https://api.github.com/users/akka/received_events","type":"Organization","site_admin":false},"private":false,"html_url":"https://github.com/akka/akka","description":"Akka Project","fork":false,"url":"https://api.github.com/repos/akka/akka","forks_url":"https://api.github.com/repos/akka/akka/forks","keys_url":"https://api.github.com/repos/akka/akka/keys{/key_id}","collaborators_url":"https://api.github.com/repos/akka/akka/collaborators{/collaborator}","teams_url":"https://api.github.com/repos/akka/akka/teams","hooks_url":"https://api.github.com/repos/akka/akka/hooks","issue_events_url":"https://api.github.com/repos/akka/akka/issues/events{/number}","events_url":"https://api.github.com/repos/akka/akka/events","assignees_url":"https://api.github.com/repos/akka/akka/assignees{/user}","branches_url":"https://api.github.com/repos/akka/akka/branches{/branch}","tags_url":"https://api.github.com/repos/akka/akka/tags","blobs_url":"https://api.github.com/repos/akka/akka/git/blobs{/sha}","git_tags_url":"https://api.github.com/repos/akka/akka/git/tags{/sha}","git_refs_url":"https://api.github.com/repos/akka/akka/git/refs{/sha}","trees_url":"https://api.github.com/repos/akka/akka/git/trees{/sha}","statuses_url":"https://api.github.com/repos/akka/akka/statuses/{sha}","languages_url":"https://api.github.com/repos/akka/akka/languages","stargazers_url":"https://api.github.com/repos/akka/akka/stargazers","contributors_url":"https://api.github.com/repos/akka/akka/contributors","subscribers_url":"https://api.github.com/repos/akka/akka/subscribers","subscription_url":"https://api.github.com/repos/akka/akka/subscription","commits_url":"https://api.github.com/repos/akka/akka/commits{/sha}","git_commits_url":"https://api.github.com/repos/akka/akka/git/commits{/sha}","comments_url":"https://api.github.com/repos/akka/akka/comments{/number}","issue_comment_url":"https://api.github.com/repos/akka/akka/issues/comments{/number}","contents_url":"https://api.github.com/repos/akka/akka/contents/{+path}","compare_url":"https://api.github.com/repos/akka/akka/compare/{base}...{head}","merges_url":"https://api.github.com/repos/akka/akka/merges","archive_url":"https://api.github.com/repos/akka/akka/{archive_format}{/ref}","downloads_url":"https://api.github.com/repos/akka/akka/downloads","issues_url":"https://api.github.com/repos/akka/akka/issues{/number}","pulls_url":"https://api.github.com/repos/akka/akka/pulls{/number}","milestones_url":"https://api.github.com/repos/akka/akka/milestones{/number}","notifications_url":"https://api.github.com/repos/akka/akka/notifications{?since,all,participating}","labels_url":"https://api.github.com/repos/akka/akka/labels{/name}","releases_url":"https://api.github.com/repos/akka/akka/releases{/id}","created_at":"2009-02-16T12:51:54Z","updated_at":"2015-11-18T12:26:48Z","pushed_at":"2015-11-18T11:01:12Z","git_url":"git://github.com/akka/akka.git","ssh_url":"git@github.com:akka/akka.git","clone_url":"https://github.com/akka/akka.git","svn_url":"https://github.com/akka/akka","homepage":"http://akka.io","size":177266,"stargazers_count":4716,"watchers_count":4716,"language":"Scala","has_issues":true,"has_downloads":true,"has_wiki":false,"has_pages":false,"forks_count":1412,"mirror_url":null,"open_issues_count":775,"forks":1412,"open_issues":775,"watchers":4716,"default_branch":"master"}},"base":{"label":"akka:release-2.3-dev","ref":"release-2.3-dev","sha":"eb1d31ee8d1018843bd2692a92b76b243837d627","user":{"login":"akka","id":1496237,"avatar_url":"https://avatars.githubusercontent.com/u/1496237?v=3","gravatar_id":"","url":"https://api.github.com/users/akka","html_url":"https://github.com/akka","followers_url":"https://api.github.com/users/akka/followers","following_url":"https://api.github.com/users/akka/following{/other_user}","gists_url":"https://api.github.com/users/akka/gists{/gist_id}","starred_url":"https://api.github.com/users/akka/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/akka/subscriptions","organizations_url":"https://api.github.com/users/akka/orgs","repos_url":"https://api.github.com/users/akka/repos","events_url":"https://api.github.com/users/akka/events{/privacy}","received_events_url":"https://api.github.com/users/akka/received_events","type":"Organization","site_admin":false},"repo":{"id":130013,"name":"akka","full_name":"akka/akka","owner":{"login":"akka","id":1496237,"avatar_url":"https://avatars.githubusercontent.com/u/1496237?v=3","gravatar_id":"","url":"https://api.github.com/users/akka","html_url":"https://github.com/akka","followers_url":"https://api.github.com/users/akka/followers","following_url":"https://api.github.com/users/akka/following{/other_user}","gists_url":"https://api.github.com/users/akka/gists{/gist_id}","starred_url":"https://api.github.com/users/akka/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/akka/subscriptions","organizations_url":"https://api.github.com/users/akka/orgs","repos_url":"https://api.github.com/users/akka/repos","events_url":"https://api.github.com/users/akka/events{/privacy}","received_events_url":"https://api.github.com/users/akka/received_events","type":"Organization","site_admin":false},"private":false,"html_url":"https://github.com/akka/akka","description":"Akka Project","fork":false,"url":"https://api.github.com/repos/akka/akka","forks_url":"https://api.github.com/repos/akka/akka/forks","keys_url":"https://api.github.com/repos/akka/akka/keys{/key_id}","collaborators_url":"https://api.github.com/repos/akka/akka/collaborators{/collaborator}","teams_url":"https://api.github.com/repos/akka/akka/teams","hooks_url":"https://api.github.com/repos/akka/akka/hooks","issue_events_url":"https://api.github.com/repos/akka/akka/issues/events{/number}","events_url":"https://api.github.com/repos/akka/akka/events","assignees_url":"https://api.github.com/repos/akka/akka/assignees{/user}","branches_url":"https://api.github.com/repos/akka/akka/branches{/branch}","tags_url":"https://api.github.com/repos/akka/akka/tags","blobs_url":"https://api.github.com/repos/akka/akka/git/blobs{/sha}","git_tags_url":"https://api.github.com/repos/akka/akka/git/tags{/sha}","git_refs_url":"https://api.github.com/repos/akka/akka/git/refs{/sha}","trees_url":"https://api.github.com/repos/akka/akka/git/trees{/sha}","statuses_url":"https://api.github.com/repos/akka/akka/statuses/{sha}","languages_url":"https://api.github.com/repos/akka/akka/languages","stargazers_url":"https://api.github.com/repos/akka/akka/stargazers","contributors_url":"https://api.github.com/repos/akka/akka/contributors","subscribers_url":"https://api.github.com/repos/akka/akka/subscribers","subscription_url":"https://api.github.com/repos/akka/akka/subscription","commits_url":"https://api.github.com/repos/akka/akka/commits{/sha}","git_commits_url":"https://api.github.com/repos/akka/akka/git/commits{/sha}","comments_url":"https://api.github.com/repos/akka/akka/comments{/number}","issue_comment_url":"https://api.github.com/repos/akka/akka/issues/comments{/number}","contents_url":"https://api.github.com/repos/akka/akka/contents/{+path}","compare_url":"https://api.github.com/repos/akka/akka/compare/{base}...{head}","merges_url":"https://api.github.com/repos/akka/akka/merges","archive_url":"https://api.github.com/repos/akka/akka/{archive_format}{/ref}","downloads_url":"https://api.github.com/repos/akka/akka/downloads","issues_url":"https://api.github.com/repos/akka/akka/issues{/number}","pulls_url":"https://api.github.com/repos/akka/akka/pulls{/number}","milestones_url":"https://api.github.com/repos/akka/akka/milestones{/number}","notifications_url":"https://api.github.com/repos/akka/akka/notifications{?since,all,participating}","labels_url":"https://api.github.com/repos/akka/akka/labels{/name}","releases_url":"https://api.github.com/repos/akka/akka/releases{/id}","created_at":"2009-02-16T12:51:54Z","updated_at":"2015-11-18T12:26:48Z","pushed_at":"2015-11-18T11:01:12Z","git_url":"git://github.com/akka/akka.git","ssh_url":"git@github.com:akka/akka.git","clone_url":"https://github.com/akka/akka.git","svn_url":"https://github.com/akka/akka","homepage":"http://akka.io","size":177266,"stargazers_count":4716,"watchers_count":4716,"language":"Scala","has_issues":true,"has_downloads":true,"has_wiki":false,"has_pages":false,"forks_count":1412,"mirror_url":null,"open_issues_count":775,"forks":1412,"open_issues":775,"watchers":4716,"default_branch":"master"}},"_links":{"self":{"href":"https://api.github.com/repos/akka/akka/pulls/18951"},"html":{"href":"https://github.com/akka/akka/pull/18951"},"issue":{"href":"https://api.github.com/repos/akka/akka/issues/18951"},"comments":{"href":"https://api.github.com/repos/akka/akka/issues/18951/comments"},"review_comments":{"href":"https://api.github.com/repos/akka/akka/pulls/18951/comments"},"review_comment":{"href":"https://api.github.com/repos/akka/akka/pulls/comments{/number}"},"commits":{"href":"https://api.github.com/repos/akka/akka/pulls/18951/commits"},"statuses":{"href":"https://api.github.com/repos/akka/akka/statuses/369c1dd643666d29a25cd119b957c5087d58ff95"}}}}