added a slug list route

src/Aggreact.hs

@@ -35,6 +35,7 @@ import           Servant.HTML.Blaze
 
 type CommentAPI =
   "comments" :> Capture "slug" Text :> Get '[HTML] CommentPage
+  :<|> "slugs" :> Get '[JSON] [Slug]
   :<|> "comments" :> ReqBody '[JSON, FormUrlEncoded] NewComment :> Post '[JSON] Comment
 
 data Conf = Conf { port :: Int }
@@ -45,11 +46,15 @@ showComments db s = do
   now <- liftIO getCurrentTime
   return CommentPage { url = s, viewTime = now, comments = cs }
 
+listSlugs :: DB Comments -> Handler [Slug]
+listSlugs = liftIO . slugs
+
 api :: Proxy CommentAPI
 api = Proxy
 
 server :: DB Comments -> Server CommentAPI
 server db = showComments db
+            :<|> listSlugs db
             :<|> liftIO . createNewComment db
 
 app :: DB Comments -> Application

src/Aggreact/Comments.hs

@@ -40,6 +40,7 @@ module Aggreact.Comments
     -- * Operations
   , initDB
   , createNewComment
+  , slugs
   , getCommentsBySlug
   , getCommentsByParentId
   ) where
@@ -199,6 +200,9 @@ createComment = modify . IxSet.insert
 updateComment :: Comment -> Update Comments ()
 updateComment comment = modify (IxSet.updateIx (id comment) comment)
 
+getSlugs :: Query Comments [Slug]
+getSlugs = (fmap fst . IxSet.groupBy) <$> ask
+
 commentById :: Id -> Query Comments (Maybe Comment)
 commentById cid = do
   comments <- ask
@@ -219,6 +223,7 @@ $(makeAcidic ''Comments [ 'createComment
                         , 'commentById
                         , 'commentsByParentId
                         , 'commentsBySlug
+                        , 'getSlugs
                         ])
 
 -- * Operations
@@ -233,6 +238,9 @@ createNewComment db (NewComment pid s txt uid) = do
   Acid.update db (UpdateComment newComment)
   return newComment
 
+slugs :: DB Comments -> IO [Slug]
+slugs db = Acid.query db GetSlugs
+
 getCommentsBySlug :: DB Comments -> Slug -> IO Comments
 getCommentsBySlug db s = Acid.query db (CommentsBySlug s)