Change how the example bot handles state

src/Haboli/Euphoria/ExampleBot.hs

@@ -7,11 +7,10 @@ module Haboli.Euphoria.ExampleBot
   ( exampleBot
   ) where
 
+import           Control.Concurrent
 import           Control.Monad
 import           Control.Monad.IO.Class
-import           Control.Monad.Trans.Class
-import           Control.Monad.Trans.State
-import qualified Data.Text                 as T
+import qualified Data.Text                as T
 import           Data.Time
 
 import           Haboli.Euphoria
@@ -22,8 +21,6 @@ data BotState = BotState
   , botListing   :: Listing
   } deriving (Show)
 
-type Bot = StateT BotState (Client T.Text)
-
 -- | A small example bot. Takes a room password as its first argument. You can
 -- run this bot in [&test](https://euphoria.io/room/test) like this:
 --
@@ -35,21 +32,25 @@ exampleBot mPasswd = do
     respondingToBounce mPasswd $
     respondingToPing nextEvent
   listing <- preferNick "ExampleBot" $ newListing initialEvents
-  void $ runStateT botMain $ BotState startTime listing
+  stateVar <- liftIO $ newMVar $ BotState startTime listing
+  botMain stateVar
 
-botMain :: Bot ()
-botMain = forever $ do
-  s <- get
-  let name = svNick $ self $ botListing s
-  lift $ respondingToCommands
+botMain :: MVar BotState -> Client T.Text ()
+botMain stateVar = forever $ respondingToPing $ respondingToCommands nextEvent $ do
+  state <- liftIO $ readMVar stateVar
+  let name = svNick $ self $ botListing state
+  pure
     [ botrulezPingGeneral
     , botrulezPingSpecific name
     , botrulezHelpSpecific name "I am an example bot for https://github.com/Garmelon/haboli/."
-    , botrulezUptimeSpecific name $ botStartTime s
+    , botrulezUptimeSpecific name $ botStartTime state
     , botrulezKillSpecific name
+    , cmdSpecific "hug" name $ \msg -> void $ reply msg "/me hugs back"
     , cmdGeneral "hello" $ \msg ->
         void $ reply msg $ "Hi there, " <> nickMention (svNick $ msgSender msg) <> "!"
-    , cmdSpecific "hug" name $ \msg ->
-        void $ reply msg "/me hugs back"
-    ] $ respondingToPing nextEvent
-
+    , cmdSpecificArgs "nick" name $ \msg args -> do
+        s <- liftIO $ takeMVar stateVar
+        listing' <- preferNick args $ botListing s
+        liftIO $ putMVar stateVar s{botListing = listing'}
+        void $ reply msg "Is this better?"
+    ]